Are summon stats checkable in the game cuz according to the wiki iron golem (at least as a monster) has 250 death res and generally seems to be better.
Unfortunately, the summoned Iron Golem has somewhat different stats than the regular one. In particular, the resistances are weaker.
Those stats are not directly accessible in the game. But it would probably be a good idea to list the stats of all summoned creatures in the Wiki separately. I will try to add this within the next few days.