Personally I haven't really had much of a problem with any other mixups like this. The issue with anthro pics being tagged pony is if you only want to see pics that contain ponies then your only options are:
1: add "pony" to your search or filter and just ignore the anthro pics that make it through, or
2: add "-anthro, -semi-anthro, -humanized" (and maybe even more) to your search/filter instead, which means losing out on all the pics that happen to have both a pony and
an anthro or human.