come on - there are a few (really few) GOOD horsearchers, and they are a pain, but that is just what it is.
Otherwise: a HA is always less accurate than a regular archer, so they become regular archers pretty fast usually after plowing the ground with their nose when their steed drops dead... And believe me: HA are very high on the target priority list, right after naked women and archers on roofs...
If some nuts now want to make ALL useful bows 2 slots, then please lets talk about making high tier 2h and poles 3 slots, to avoid totally overpowered sword/axe or 2H/pole hybrids, and lets not forget the xbows, they all need to be 2 slots then as well...