Yes, I've run into this kind of problem too. We usually don't worry very much about row gauge but here's a pattern where you do have to think about it (as you have). I don't know what size you're making but 8.5 for the sleeve seems a little tight, I agree, even for a woman's small size. You could certainly go up on the sleeve opening. Since there's no sleeve shaping this is evern easier to do. Check that this isn't making the entire sweater too long (9rows is only ~1.5inches). The other possibility is to start the reindeer motif earlier, if you haven't already begun the front.
We'd love to see a picture of this finished sweater which sounds wonderful.