Well I'm trying to represent the unit sizes in rtw with a +/-1:4 (actually 4,166 scale) scale (on huge unit size) camillian hastati, principes and triarii were 900 men strong, polybian hastati & principes were 1200 men strong, polybian triarii however were only 600 men in strength. All this would require to have seperate camillian and polybian units.
So my sugestion for the unit sizes is:
Equites Extraordinarii 144
Pedites Extraordinarii 200 (2 units per army)
Cam. Hastati 216
" Principes 216
" Triarii 216
" Equites 72
" Rorarii 216
" Leves 72
" Accensi 216
Pol. Hastati 144
" Principes 240 (or 288 if someone fixes the launcher)
" Triarii 240 (or 288 if someone fixes the launcher)
" Equites 72
" Velites 240 (or 288 if someone fixes the launcher)
" Allied Hastati 144
" " Principes 240 (or 288 if someone fixes the launcher)
" " Triarii 240 (or 288 if someone fixes the launcher)
" " Equites 216