Better play safe with full compatibility. That’s what people expect should they play with your fixes or mod, no matter what you personally like or not. A new class isn’t really worth it that the AI will play even worse than it already does. I haven’t studied how or if at all the AI handles different classes in the code. Who knows what funny things happen with new classes?
Something else: does it make sense to create more sniper variants for each year (currently only Japanese and US Marine Scouts)?
They have only 3 inf-att. This gives a 1:0 first-strike prognosis against infantry ‘37 units with inf-def 9. All infantry-class units with year-variants get an increase in attack and defense that the poor snipers won’t do damage anymore and get easily pawned in late-war. 45er inf-att 16 vs. sniper inf-def 2 = ouch!
I see the point that towed guns and structures could easily get smashed by snipers later, so increasing their attack could be only one point per two years, but their defense should really be improved over the years, similar like the commando units. What snipers rather do is reducing the efficiency by killing officers and not wiping out battalions, but a little damage could never hurt over the years.
If you follow the same progression like commando units, snipers could look like this:
Theoretical commando 37: inf-att 4-6, inf-def 3, veh-def 14
Sniper 37: inf-att 3, inf-def 2, veh-def 13
Sniper 39: inf-att 3, inf-def 3, veh-def 13
Sniper 40: inf-att 4, inf-def 4, veh-def 14
Brit Cmd 40: inf-att 6-8, inf-def 5, veh-def 15
Sniper 41: inf-att 4, inf-def 5, veh-def 14
Sniper 42: inf-att 5, inf-def 6, veh-def 15
Sniper 43: inf-att 5, inf-def 7, veh-def 15
Sniper 44: inf-att 6, inf-def 8, veh-def 16
Sniper 45: inf-att 6, inf-def 9, veh-def 16
Brit Cmd 45: inf-att 11-13, inf-def 10, veh-def 17
This way, snipers have a similar good defense against vehicles like commandos as camouflaged units.
I guess adding more bunkers and mg-nests with inf-att/def increase over the years possibly would also make sense to counter the infantry improvements.