You are wrong, Assasinate does not require surprise. It works as long as the enemy hasn't taken a round in combat yet. So winning initiative should be enough to attack with advantage, and autocrit. Bam!!! 6D6+Dex.
It would be fixed by limiting the autocrit to surprise attacks I think.
It was one paragraph, and I wasn't able to read it rite.
There goes my internet pride.
but at least the universe has balance again.