Which is your preferred style in army composition? Normally, I raise a couple of all-rounded at least 20k attack armies (about 10k inf, 6k cav, 4k arty) to beat enemies in the field and lay siege, commanded by the best generals I can afford, and a bunch of smaller (5-7k) armies, almost all infantry with the occasional 1 or 2k cav to act as a mobile defence force; occasionally I raise also a medium-sized (5 to 10k) all cav force to raid deep inside enemy territory. I know it's quite an expensive way of doing, and that it takes quite a lot to be built, but it usually gives the advantage of quickly gaining the key objectives on the offensive while still affording good defence (I move def infantry on internal lines, so I can place them where I really need, grouping and finng their ranks with new troops when necessary), and I think that the best way to economise on your military budget is keeping the wars you fight as short as possible. Another point is that if you defend well your borders with modile troops, you don't need to invest too much in fortifications, and a third one is that you can easily bolster your offensive first line composite armies with the second line infantry (remember that grunts are the ones that suffer the most form battle damage).