Since henchmen are only used during battle. I suggest that you put another store next to the Crown Store at the top of the page for henchmen. This would help speed things up in selecting hechmen because you could put them all on one or two pages (or use tabs for each level such as lvl 10, 20, e.g.). Also, it would make things faster since there aren't as many items to load up in the store.
Again, you could call this store like Henchman Shop or something like that.
I forgot to add to the above suggestion that you could use one page and display all the henchmen in a grid-like formation with levels as the x axis and the types of henchmen as the y axis.
