Comment by lazy_afternoons

Completely Agree.

Both Romans and Mongols have lost/retreated many battles. They just had to regroup and raise another army over and over again. Some of their opponents could not even afford the war even after winning over them multiple times.

The other sides simply were more fragile, where you were defending and once your city falls, you are done.

Avoid risk of ruin. Keep the ability of taking multiple shots with upside in your favor.