I played some siege for the first time with the new patch and just after a couple of maps I feel a few things could change.
-Respawn time set to 15sec, at the most 20sec.
-Both teams either have unlimited lives or each have a set amount, even if the D has 5 and Attackers have 8. I understand attacking may die more just by archers at the start so give them some more lives to make up for that.
-If the lives don't change, make the rounds shorter. This way the D stands more of a chance rather then holding out till the last minute every round and losing because either everyone ran out of lives or is stuck in a 30sec spawn.
-Alternate teams from attacking to defense every round. That way everyone gets a chance to be attackers and defenders.
That's all I can think of right now, but those issues is what really jumped out to me. Siege has always been attacker friendly but with the multiplyer it just pads their xp/gold.