Fryon is correct. What I have done is to use Large WP's with weapons, combined with Small WP's with armor/shields and maybe a weapon or something, calculated so that my "soak platforms" have less structure than my weapon-bristling WP's.
I agree with Rex that the WP hit should be randomized. This has been a request into MM for a long long time, but apparently it hasn't bubbled high enough to get done - making WP's hit first is as close as we've got, and it just occurred in the Last patch.
As for the numbers below, it didn't include training for +40 or more.
The real problem is the fundamental one with the whole to-hit mechanic in SE4. FACTORS should MULTIPLY and NOT ADD! I wrote several mathematical emails to MM about that and finally gave up. It would massively help out the balance of play, but it would also stand everything on its head. Maybe for SE5...
PvK