The only mathematical fact of squad size is that 6 men squads are better. When reinforcement cost is determined based on squad size there is ZERO possibility the cost is balanced.
Except its not based just on squad size, total cost of the squad matters as well you know.
And guess what, it is balanced in all infantry combat engagements. You'll found out why soon.
Why you ask?
Because our best example, Grenadiers at vet 0 vs conscripts at vet 0 is a 50/50 engagement determined by cover and RNG. Either side costs 240 MP, and has an equal chance of winning. Then you factor in the other positives and negatives such as DPS dropoff per model, squad recrewing, literally any explosive or ballistic weapon that can wipe multiple units and the conclusion is: 6 > 4.
Incorrect, its 50/50 only around mid range.
Long range, grens will always win, short range, cons -should- win. Then come weapon upgrades and we have grens stomp cons unless cons embrace doctrine to even stand a chance. Upgrades, in this particular example, throw your argument out of the window, because now its cons who are losing significant DPS with each model lost, while grens not really due to most DPS being concentrated around one model.
Squad spacing changes invalidate argument about ballistic explosions, unless you really like to stick to very small yellow cover spots.
Since we have to talk in context of each faction and its options as well, grens have fastest access to on field, mobile reinforcement, making recrewing non factor, unless for whatever reason you try to do it under heavy fire, in which case "steal" attempt will not work regardless of how many initial models squad performing it has.
Conclusion:
4<6 exclusively when trying to steal HMGs under concentrated fire and further faction options make up for smaller squads in context of wehr, UKF doesn't have that kind of options, but they can bolster themselves to 5 men at hefty cost.
The problem with "I have more models therefore I should have a cheaper reinforce" excuse is this: "I want a 100 man squad but the reinforce cost should be 1.2" Same cost as grenadiers, we can nerf model stats to be equal to grenadiers, but the difference is that squad will NEVER be wiped with any ballistic or explosive unit, it will also be great for recrewing things (although if model stats were that bad they'd disintigrate under any means of fire, but this is obviously an exaggeration).
You think 6 man squads aren't getting wiped by explosives?
For real?
And you're talking about Osttruppen.
You want higher squad count units to suffer from attrition much more due to lower model survivability AND pay the same as other sides individual models.
You are not asking for balance, because you do not understand balance, you are asking for 4 man squads uncontested superiority and ability to inflict insufferable attrition losses.
Reinforcements are different because squad costs are different, squad counts are different AND individual models have different strengths. Reinforcing from 1 model squads of equal costs should ALWAYS cost the same, regardless of how many models squad has.