Cleric starts with blunt.
And are you still going to do your very first playthrough of the game past level 3 on Tactician? Well, okay, but you can't say that you weren't warned.
Backstab DOES work on Undead. It's just that Skeletons are resistant to piercing damage.
Just to be clear, I tend to lose interest in games (even ones that I otherwise genuinely like) at somewhere around the 30-40% mark).
For example:
I left Pillars of Eternity at the start of Act II because of some annoying-level bugs, and a bit of being overwhelmed at the size of the first large city.
I also left XCOM when the first rescue mission started - found it too difficult.
I left DOS1 playing on hard when I got to a fight that I could probably have done reasonably on medium (plus enhanced was the excuse.........)
I now see a bit of a pattern here in my playstyle - play on easy / medium, find it reasonably OK. Move to hard. Gets difficult around mid-game. Get stuck. Drop game.
However, I also tend to like fiddling around with a lot of classes, class options and class combinations. This primarily involves playing the first 10% percent of the game with a wide variety of characters to see what I like, and also how different characters play.
In general, I think your warning might help me continue with the game on a lower difficulty level.