@FtF
it would still need two creatures to don; the PC, in this case, is the seconded creature and the horse is the one needing assistance. So everything is statuesque there (I don't think their is any thing in the rules preventing a horse from donning light armor, other then the common sense of players and DM/GM and it being of too low of Intellect)
@
Axel
Also, I (Alex for that matter) would think Alen would act sneaky; why do the frontal assault/confrontation? he could instead act like he is
chasing Alexander, the crazed wizard who has just gone rogue that he has been traveling with in case of this very possibility, until he needs to act one way or the other, possibly avoiding conflict and slipping away, or giving himself a advantage later by flanking them when they move into melee with Alex. Also, neither of you two have a horse, you're assuming two are handy. meanwhile the town is panicked about a crazed wizard* and his Gnoll servant and likely overeager for skilled help, and even if they don't fall for the ruse the frontal option is still open ^_^;
[*could even have a lot of fun with this, this is a case were Alden can paint Alexander however he wants without lasting repercussions; Alex has given him a lot of room to work if he works outside of the box, but almost none if Alden works from within it like a fighter or barbarian who can do the whole "Hulk SMASH!" thing and just power through a mob instead of slipping through it.]
But that is just my two cents :3