Well...shortish (under 44 inches) blades/sticks can ( should) be wielded/controlled by light ,balancing, hand control pivoted on the left hand.(sword/shinai/boktu). A shorter weapon "cutting inside" any of these needs better timing , it can be done but requires experience and practice. Spear versus sword would I assume therefore need "avoidance of the point" (of the spear) , thats the whole of the sword technique reduced to one phrase ( push the opponents point away from a centered position) and cut or stab him with your own weapon which is occupying the centre.Now of course this is one versus one , but if I had a reasonable shield I would be quite happy to try to wait for an opening and strike the point out of centre by whatever means are needed -once inside the contact zone I would be confident of either striking or pushing the enemy backwards.
So ..in formation facing multiple points? Interesting , re-enactment is what we need here, but the "fix and flank " rule of Virgil is most important. Velites/any pre-contact attrition on the Phalanx looks more important to me now. Break no fracture ,the monolith and I suggest you can hack away and destroy it at speed.