Gun autism incoming:
Just because it's called a sub-MACHINEGUN it is not the same.
In german for example it is called "Maschinenpistole". Literally translated to "Machine Pistol".
BTW the german MP18 was the first real Sub-Machine-gun by how we are using the term today as most pistol caliber automatic weapons were usually mounted weapons. One could argue that the germans therefore invented the concept of the "SMG" and named it a Machine Pistol, not a Machine gun.
And in their use they differ a lot too. The Fun Pimps don't know much about guns either as it seems (Those "iron sights" are the main reason I was looking at your mod and I am loving it). An Assault Rifle, like the AK-47 and M4 from the Vanilla game is used very differently and handled very differently from the M60.
If you would want to be hyper realistic, you would have to put SMGs, Pistols, Assault Rifles and MGs all in different categories.
There is also the topic of crafting and parts. The MP5 and the UZI are both recoil operated guns, which is a mechanism that is closer to your typical handgun like the M1911 or USP. Since the skill determines crafting and what parts you need to use, it would make more sense to put them into the pistol category too, because the mechanisms are more similar between a UZI and a M1911 than between an UZI and an AK-74. However there are SMGs that are gas operated, thus being more similar to most Assault Rifles.
There is also this part from the Wikipedia Article on Submachine guns:
A
submachine gun (
SMG) is a
magazine-fed
automatic carbine designed to fire
handgun cartridges. The term "submachine gun" was coined by
John T. Thompson, the inventor of the
Thompson submachine gun,
[1] to describe its design concept as an
automatic firearm with notably less
firepower than a
machine gun (hence the prefix "
sub-").
As a machine gun must fire rifle cartridges to be classified as such, submachine guns are not considered machine guns.
The last sentence is the important part here.
Loving your mod anyways. And I am not forgetting that balancing is also a thing and giving one weapon category too many weapons while the other doesn't get any, wouldn't be fun either.
Giving the Pistol skill a high caliber option would be more fun anyways. The vanilla game already gives us the option to either take Desert Vulture or SMG5. Having the Option to take a 9mm/.45 pistol, or a high caliber weapon like the Desert Eagle, Colt Anaconda... which are both in vanilla but in a terrible condition.
