Some decent choices there mate, I suppose the only reason you'd want to take a butcher over a slaughtermaster is for the maw......but I've never been lucky with it to be honest ( best I ever did was kill 2 kurnoth hunters for 10 wounds) and I've been playing aos since it came out.
Tyrants are mint now we have an update....but I always find myself giving him the fateseeker big name (3+ save) as he's usually sniped in my battles. I suppose if you want to go gnoblar heavy hes an absolute must have in the army.
Gluttons are quality but only in a 12 block.....the discount you get from 9 to 12 is very good. I've been very impressed with leadbelchers....they are my objective holders as they pepper the enemy with d6 shots a piece before still hitting really hard in combat (actually prefer the -1 rend of the leadbelcher over the extra attack of a glutton). Iron guts are well hard, you need them with so much rend out there now. I use 1 unit of 4 and find that's enough to get the job done.
Frostlord on stonehorn is unreal mate, always wipes the floor with most of my opponents but you gotta lose a lot of good objective holders in your list to field one.
Never used a hunter or sabers before, wasnt a fan of the models but I have heard good things about them from tournament players