If they had a bigbrain or took some time to think, they could dash and jump to hide in the building on the left and wait for all the goblins to leave the roofs, then kill them one by one as they approach. Larian gameplay is just goofy and they aimed at showing new abilities there.
The forum ate my initial response going through the PfH's Tactician sequence - quotes, timestamps and all. The funny thing about that sequence (starting around 5:55:00 iirc) is that what the dev says aloud while playing doesn't match the on-screen action.
He says (more or less) "unlike these guys, I decided to get ahead of the game by sneaking around the goblins", but as 3rd player dropping in, he just appears behind the enemy lines, no sneaking involved. He adds (paraphrasing), "See, the goblins don't see me right now, but they're locked in combat so that gives me the opportunity to get a cheeky little shot off", but he doesn't realize combat is over because his companions are dead. The reason goblins aren't attacking is the've never seen him before, so they have neutral approval towards him.
Two conclusions : Looking at the video, I agree with your assessment that cheese isn't necessary to solve Tactician mode; listening to the audio, Tactician doesn't seem to discourage cheese either. I was hoping Larian would design Tactician to punish certain overly simple and effective strategies. I don't think that's what we're getting, though I could be wrong if Full Action Hide only applies to Tactician (@Tuco timestamp 5:58:02 for that confirmation). Whatever, it'll be normal mode for me. No big deal.
