The two dragons are racial heroes, those guys are bonus meat grinders. About equal in strength is a rather inaccurate description as well. The tougher of the two dragons is 23 strength. Meshabber clocks in at 31, uses weapons for 35 with mythril, and has divine fire 2. Comparing them is like saying Saverous is a match for Mardero. The mithril golem is a little more reasonable a comparison in stats, divine earth 3 isn't that useful to account for a 150% increase in build. On the other hand, you've got an edge as kilmorph that Meshabber can't share, and that the dragons need serious effort to share. Heal requires summoning or divine life 3, repair just needs a dwarf with enchantment 1. Practically speaking, the Mithril golem is always going to be at full strength when the enemy moves. What he lacks in brute strength is made up for in being guaranteed to be in good order every turn.
I don't particularly like the 5k hammers though. They're already rather difficult to obtain, 2k would be a much nicer number. The Mithril golem is a little lower in class, but as kilmorph you're not exactly going to be short on production. Being specific to a particular city you can't just build it from a super production power, as you'd need your religion to have popped in a particularly good location. The 200 hammer dwarf city of doom that got built in floodplain mountain tiles wont be much use unless it's the 200 hammer dwarf city that got the religion pop.