How about having the golems be proportional to your level, with a minimum level of 1 and maximum level of 55?
Say, for thief, spy, messenger and bodyguard, they can range from 5 levels below your level, to 5 levels more than your level.
So a level 5 player might have a spy golem at level 1, or a bodyguard golem at level 10. That way, they can level the golem proportionately, and it won't hog all the xp.