Pig, that hurrIV (aka HurrIId) may have had different configurations, weights, armor plating since it was ground attack, etc.
The Hurr2 A, B, and C, were the same plane with different weapons. Very little other difference. You might argue certain tropical filters, but these were across all makes and models, not specific to (i.e.) just the Hurr2A.
Why bother splitting them up? It's really the same plane, same engine, same capabilities, just different guns. It would be like splitting up the P-51D into 2 planes, one with 4x 50cal, the other with 6x50cal.