Everyone definition of fun doesn't follow the same guideline and 100% lonewolf clear is one of the hardest accomplishment in the game especially when you consider that it doesn't work against bosses, forcing you to change your entire skill set and plan when it's down to a 1 v 1.
Guerilla tactic is a legit strat in a real world to thin out a herd and win with lower number. Why wouldn't it be a legit strat in Divinity now that has a bunch of logic-based strat like using environment effect? Not everything is an exploit just because one side figured out how effective they can be. If it was not intended and indeed an exploit, Larian wouldn't remove that 1 source Point cost from Sneak which allowed the strat to work at every encounter.
I said that I thought it was fine, but that if it was a problem (or rather, if Larian considered it a problem), they could do something about it.
Also I think you confused Sneak with Walk in Shadows, as Sneak never had a Source point cost, the invisibility skill Walk in Shadows did (and was useless because of it).
