Yeah. I dunno about killing the bard as often as he kills you. Unless you're Hunsobo/Igbah/Woldrun or something.

Both parties know a fight's going to happen -> thinking this favors bard.

He can adjust size, meaning you'll need to spend time looking at him first to figure out how you should adjust yours. He can also potentially prep more than the warrior. Then again, warrior will have resist mental in this scenario.

Giant ambushes bard -> obviously favors giant, but I'm thinking his advantage is smaller than the opposite scenario where bard ambushes giant. In the former, it basically boils down to whether giant can bash bard into the ground. If not, then bard gets away, assuming we're not in some cursed terrain. In the latter, it boils down to whether bard lands sleep. If he does, then giant's probably toast unless he calls in a rescue. Esp. if bard has scrolls/talismans on hand.

Then again, most likely giant's calling in reinforcements ASAP after getting slept.