Hmm, the map does appear to be rather stuffed with IIIs and IVs, but in my own testing (with two starfleet commander AIs 7.6 and 7.3) this appears to be "normal"; it may be that "normal" has been buggily inflated lately, not sure. Anyway, here are the results I got:
That seed, X map type:
1/33/57/28 (that's 1 Mark I planet, 33 Mark II planets, 57 Mark III, 28 Mark IV)
Same seed, simple map type:
4/24/59/32
Different seed (70312500), simple map type:
3/30/59/27
Different seed (70312500), X map type:
1/35/57/26
So they all look sane in comparison with one another.
Does it seem like all maps have more IIIs and IVs than they should?