Ok just to clarify the air, I am an ex-military of the Canadian Armed Forces from the 80's....so my knowledge is dated, I believe the current designation for the combat arm of the US military right now is the M4, the M1 Garand was the rifle from WW2 bolt action with a 9 round strip clip to reload....a very good gun for it's time. I do think .....and this is just a opinion because I have not researched it, but I believe the only use the M16 for training battalion and National Guard reserve units, quite possibly for the Marines as they only get hand me downs from the Ordinance Corp of the Army in charge of their supply and only if the Nave is allowing them more them bows and arrows this month, ( for those of you that cannot figure it out this is a joke that most Marines will recognize). I do see the little knife that is inside Machetes coat and yes it is similar shape but not quite as curved or long as the one in 7 Days to Die, of course the one I choose for my example is the full size version of the Kukri, not the normal 12" one of the Regiment. Unfortunately most people have only video games and movies to go by and don't understand the heritage that comes with certain weapons, and it is for that reason as well as to see if the developers would answer as to why they choose this particular shape to be the Machete. As well I would ask where you were from because the last time there was a draft or conscripting in the USA was the 60 and 70's for the vietnam war, I do believe all of their armed forces are volunteers.
i'm from Poland and we talk about "zombie situation" not typical enemy like russians - cops send redneck to fight with zombies in 1978 dawn of the dead and probably in l4d2 (this is theory) so well against zombies everyone is soldier and usefull. Now about guns - i mean more as "aestetic and if we can use this for free" stuff that technical stuff- honestly in Poland before WW2 we had +- diffrent bolt action rifles. So it was a mess.
And why M16 could be better in 7dtd ? because" eastetic" - the best example will be
Military Base | Painkiller Wiki | Fandom it have even similiar graphic.
M16 suits to USA army , survivors and PMC. MP5 this + bandits. AK47 to "exsoviet" countries and africa.
In cod WW2 you can find on omaha beach ppsh . In next mission- SWT. If it could be there? yeah but not in such a number - but G43 is missing and that's hurt a lot.
in cod cw in firebase Z you have OMEGA soldiers ( special unit of KGB) with american gun ( it could use it ofc but it's looks stupid).
In contagion you can find M1 garand and it'suits good - you have old houses, guns shops etc. it's looks logical - but mp40 could looks stupid.
In cod MW2019 you have K98 and MG34 - okay this have sense - a lot of this guns were send on east. But blunderbuss would not suit good right?
Honestly it is shame that a lof of vietnam games doean't have for example mosin , ppsh for vietcong. But it understand why so they put the most iconic guns.
Do you know that Valve add to L4D2 cars from 60-80' because of law?
So - AK 47 could be better after nukes but M16 more suit to this setting.
I think they add this shapes because it's looks rly cool and "post apo"