Ok according to video I'll tell you what I see as mistakes : (its up to you to take it serious)
1 Bad equipment, nomad bow = no good, we didn't even use that stuff in the first fief battles.
2 Ladder spam, you used most of your ladders at the same time, I see 1 man on 1 ladder so you've lost most of your ladders at the same time.
3 Bad ladder positioning, almost all of are at the same place but not in the correct place
4 No siege shields around siege equipment, well I heard something like catapult got destroyed by itself even if its true, I say defender ranged helped a lot.
Last and the most important one is, you seemed to hasty in your decision. I believe conquering some villages would be more use for you.
Good luck next time.