I really like this game! After trying so many different strategies this is the best I managed to get (lvl 154). Most of my equipment is mythic, with all Dwarves fitted with Mug of Everlasting Bock and Cane of the Ancient (all Legendary and above). This level was actually the first deserted battle I had :(
I tried it 8 times using different strategies (got the closest using this setup). Still not convinced that this was the best setup, but the Guardian just wasn't doing anything in the end.
Hint: Make sure when your Dwarf is about to upgrade, make the main weapon wisdom based and early on, use the most appropriate artifact that suits the dwarf you are trying to create - Doing this, the lowest wisdom was my warrior with 50 wisdom. But I do wish I had started 'sacrifice' runs about 20 levels earlier to activate Mug for additional wisdom - I think probably Guardian is the way to go, but I was getting toasted!
The only suggestion is to make Mythic Equipment much higher stats. They seem to overall only be about 2 stats higher than legendary.
Congrats on a great game!