First, the priests seem to be able to heal some of them but not all of them. Bug or design? Seems more like a bug.
Secondly, don't you guys think that these converted animals take up way too much pop space? Also why can't we convert them when we are already at pop limit or when converting would take us over the pop limit. It would have been nice to be able to ignore the pop limit and afford a much larger army. The negative side would be that you can't make anything else until you either get more TC's/Houses or get some of them killed.
Thirdly, you can't attack a charmed enemy animal with your priests - they try to convert them back while they get killed. So Set's priests are useless vs. other Set's converted animals.