I'd say if anything, remove the polestagger from all polearms, except a few 2-directional ones. The real problem is those stupid moments you are stunlocked by whatever small stick is capable of that... Or when the stagger makes hiltslashing with a GLA-like waaaaay too easy.
The issue with pikes and long spears isn't as serious IMO. Those two should be strong teamplay weapons and useless without teammates. Removing the jump with them seems like a good idea. Also, increase their weight.