oK, now this have more logic for me.
When I think in a counter-infantry infantry unit i think in something like the shieldman i mention here: Soft Barracks Rework - #19 by Martinurello
In resume, soldiers with a huge shield and a short spear. Not specially high HP but very high melee armor, Mid/high PA and bonus vs infantry. It could share the spearman armor class with pike-line, sharing the same counters.