Civ 4 system is good, not because of having a "stregth" value , it is because of the counter-system :
"X get bonus against Y" , which is what make the system great!
Gunship > Tank > Sam Infantry > Gunship...
Axeman > Swordman > Longbowman > Axeman
"X get bonus against Y" , which is what make the system great!
Gunship > Tank > Sam Infantry > Gunship...
Axeman > Swordman > Longbowman > Axeman