The 1911 would be awesome but I wish that they would have just put it in the first place. The 1911 is one of the best pistols made to date, that is why it has been made for over a century now and some american spec ops still use it. It's reliable and it has wonderful stopping power!
But lets look at the pistols in this game and break them down.
Five Seve is an up and coming pistol which is proving itself to be very reliable.
Tac-45 is just a beefed up USP .45 made by H&K and could very well replace service weapons.
B23R look just like a 1911 execpt for its is a three round burst so "technically" there is a 1911 in game.
Executioner is the Judge made by Taurus and it doesn't handle like it should. With the Judge you have to options of multiple types of shotguns shell that you can use or you can shoot a .45 long colt bulit out of it. Technically this pistols should be a one shot kill just like the shotguns because the barrel is riffled meaning that it would shoot a tighter patern but it doesn't. It seems like they used bird shot for this pistols Lol.
A revoler would be an awesome choice like a .44 mag, .357 mag but i don't know if we really need a pistol. An assualt weapon like the M4 or the M416 maybe even a reall M16 variant would be nice. I would even like to see for the LMG class the M60 would be cool.