My composition of infantry divisions for majors (with some mods):
3 * Inf Brig: 3 * Inf, Inf Art, Brig Support.
Fire Brig: 3 * L. Art, H. Art, Rct.
Support Brig: 2 * Eng (maybe 1 for each of assault and bridging), Signal, Recon, MP.
Logistic Brig: Hospital, Maintenance, Logistic, AA, AT.
Or in this way:
Infantry division A:
Brig 1: 3 * Inf, L. Art, Mx Cannon (AT & AA).
Brig 2: Mix Support (2 Eng comp and 1 comp for each of Signal, Recon and MP), Mix Logistic (1 comp for each of Hospital, Maintenance and Logistic).
Infantry division B:
Brig 1: Inf, H. Art, Rct, Assault Gun, Infantry Tank.
Brig 2: Same with that in Inf Div A.
And the Ratio A : B is 3 : 1.