Overview

First and foremost, AK-74M should be understood to be a gimmick more than a crucial team building element. Her Skill buffs dolls containing 'AK' in the name, the variety increasing with Skill level. This is a fun gimmick for those who enjoy theme teams, or trying to use unconventional Echelons, but AK-74M focused Echelons will underperform against properly built AR/SMG teams. We will discuss the reasons why this is the case in the full analysis.

With that out of the way, AK-74M's other standout feature is her tiles, which buff ARs and SMGs with Damage and Crit Rate. This is obviously a powerful buff, and does help to boost her utility in her team. Her stats are fine, with a reasonable Damage and Rate of Fire, but nothing extraordinary. Her Skill passively provides her with a 5% boost to Damage and Rate of Fire per Doll using an AK weapon, including 74M herself, so she will always have a tiny bit of additional DPS in exchange for existing. If used with a traditional AR/SMG Echelon with a full collection of AK dolls (AK12/AK15/AK74U), she sits at a comfortable 20% to both stats, and will when combined with a Chip be sitting around RoF cap, so bear that in mind when team building. While this buff has the advantage of being passive instead of active, it will not be enough of a boost to keep 74M competitive with other self buffing ARs. 

Her art is cool at least.

Full analysis

Now, to back up some of the rather aggressive claims about AK-74M's skill made above. 

As stated above, 74M's Skill provides a variety of Skill augments to the various Dolls with 'AK' in their name. These are almost all useful, but none of them are revolutionary for a given Dolls role. Further, post Dual Randomness content is quite unkind to AR/SMG echelons so our AK themed team will be competing with the absolute best of the best to try and earn its place. 

AK-47:

AK-47 gets an impressive buff, switching her skill values to provide an impressive 100% boost to her Damage, and a boost to Accuracy that is almost entirely forgettable. While AK-47 takes best advantage of this boost via her Arctic Warfare Speq (VFLs with Crit Damage boosts), she can still benefit even without it. This does push AK-47's personal damage output up to respectable levels, on the back of her own relatively good Damage stat, but respectable is not good enough in the limited world of AR/SMG Echelons. One needs either to be the absolute best in their field, or have a strong useful niche that only they can perform, and merely becoming a passable DPS AR does not meet either of those thresholds. 

AK-74U:

While it is incorrect to say that 74U does not benefit from 74M, she has some of the weakest gains of the group. Converting her debuff from an active to a passive Skill means that she will have perfect uptime on single targets, which only doubles down on her existing niche or slightly kneecapping bosses, and also means that one can spread her debuff around much more easily with repeated, constant micro. However, wiggling 74U to apply her debuff to every enemy in the formation is both mind numbing and often ill advised as it impacts your ability to actually micro her as the battle demands. If your client is cooperative, and you are willing, there is some value to be gained here, but in almost every situation, simply using RO-Mod, UMP-45 Mod, or a less micro intensive HG/SMG setup is going to perform better. 

AK-12:

AK-12 gets a flat boost to critical hit damage while her Skill is active, giving her a buff to every offensive stat during her Skill window, and removing some of the penalty from running a chip. With a VFL, she will cap Crit Rate to take advantage of her slightly better Crit Damage, with the small downside of horrifically overcapping her RoF in the process. Outside of the substantial RoF waste, this does improve AK-12's Damage output nicely during the Day, with little to no benefit at night, due to the need for a PEQ. This is unlikely to put AK-12 on even footing with the meta defining DPS ARs as she lacks Special Equipment or a defined niche to stand out in the crowded field of ARs, even after this buff. 

AK-15:

AK-15 probably makes out from AK-74M the best, recieving what amounts to a 40% boost to Damage due to near perfect uptime on her Anger buff. In practice there is one shot every 3 seconds that is not buffed with Anger to reactivate it, then every shot for the following timeframe will be buffed. This is a no frills buff to AK-15, with some fractional utility when AK-15's mod arrives making it easier for her to get the boosted Damage in retaliation, but again, this is a niche-within-a-niche situation. The flat boost is not enough to pick up 74M's slack, but it is by far the most interesting boost 74M provided to a teammate thus far. 

AK-Alfa:

Ignoring the fact that the AK-Alfa is built on a Saiga receiver and not a Kalashnikov, AK-Alfa gets another boost that is good on paper but struggles to survive practical reality. Being given perfect accuracy against targets in front of Alfa sounds quite powerful, after all, sure hit attacks have been held up as a reason to use specific Dolls in the past. The devil however is in the details, in particular, that this only affects enemies in front of Alfa, a range that can be seen when her Skill activates. If she is used, Alfa tends to want to be in position 4 to get the most out of her passive, and 74M wants to take position 4 to buff both ARs with her tiles. While you can move Dolls in battle to get around this, it is more tedious and can end up creating other issues that you might want to avoid, such as misclicks, or DPS downtime, and is subject to client whims.  

Also, there are not a lot of situations that demand more Accuracy than an AR has by default after Dual Randomness. While there are occasional night missions, they are infrequent, and through Poincare Recurrence, there has not been another Night Ranking Map. While the June 2022 QnA did reveal that we will start getting ranking reruns, the Arctic Warfare and Deep Dive reruns are both Day Missions, without high Evasion enemies to give this buff a place to shine. This leaves Ak-Alfa with a neat buff that struggles to find its niche, and is not likely to create enough additional DPS to make up for the DPS lost by running AK-74M.  Also, trying to somehow abuse Alfa Unity Skill with M82 for this will only result in a worse Echelon, due to M82's aggressively middling performance, so don't even think about it. 

In Conclusion:

All of these problems are compounded by the fact that to get the most out of AK-74M you need to use her with as many of the above Dolls as possible. With only one SMG you either have to run AK-74U, who is subpar in day-to-day content or go without some of your buff to AK-74M putting even more load on her Echelon to pick up the slack. AR wise, you have more selection but are still somewhat limited. AK-12 and AK-15 are probably the most useful generalist pairings, but a backline of 74M/12/15 is going to struggle to compete with other more prominent AR groupings. To head off the idea at the pass, a fully AK Echelon with 4ARs and 1 SMG is a terrible idea. AK-47 is not going to produce enough Damage to make up for either the lack of a HG, or to save her partner from damage or to prevent herself from taking Damage, and this impacting her DPS from there. 

The inflexibility of team building underscores almost everything about AK-74M. She is aggressively pigeonholed into one of a few formations that share a similar set of problems, without any way to mitigate these problems effectively. Her Echelon will underperform when compared to other, better built teams. At its core GFL is a numbers game, and there is no fancy magic that can make the numbers of an AK-74M echelon bigger than a more traditional one.