I wouldn't say he's the greatest tactician in the world, but he does have a plan and formations. We don't have a big enough budget to have 2 first team level players for every position, and that's where it gets tough.
You might not like the quality of the players, but in the past:
He wanted pace to replace Humphrey - he brought in Ainsworth.
If he wants pace on the left, he plays ZFA.
Wanted to replace Anier, he brought in Henrik.
Needed cover in defence last season, he brought in Reid.
Needed to replace Higdon, he brought in Sutton.
As for Law, we needed to replace the creativity of Faddy (Although we can argue if he was playing as a striker or a midfielder last season)
Ojamaa came with the explicit intention of playing as a striker, so you can pretty much guarantee when he is fit (and Erwin is back fit), it will be 2 up top.
He's not perfect, but he's been our most successful manager since the war, so there is something going on there that is working.
Having said all that, I"d be surprised to see him here next season, as it's only a mtter of time before he gets the offer he can't refuse.