2 WM for 120 wpf is fine, really. You can have 33/6 which gives you lower damage output than 36/3 build. Also in order to put 2 points in WM you'll have 2 less IF, not that noticeable but better than it's now.
With this system, some builds, like pure 30/9 build might seem too OP. Mainly because they could have 175 wpf in one category and 10 PS.
But they can be easily countered by 18/18 6 WM, full wpf 1H/thrower. Hybrids get the biggest buff that way.
Only full str, no wm build, will be nerfed. Not removed, just not viable like it's now. But everything else would be buffed big time.
Also, build diversity is great on paper atm. Problem is that certain builds are so much better than the others. That's why actual build diversity is pretty bad atm. Everyone is using cookie cutter builds.
What they need to do is to actually give us less possible build diversity in theory, but balance those remaining builds so that they are all equally viable and desirable. Easier to do with smaller build pool, what we have now and poor build balance is just proof of that.