I want to start with saying I do see what you're saying with Jorgen and Borge.
That being said, with Valkryie all you miss will be the combo with Ander/Jostein, because you'll have to bring Jostein if you want the Jostein/Jorgen/Borge/Britt Combos and Ander won't do anything if you bring them in Jorgen/Borge route. And with the Onsrud, you don't have healer combos anyway, the only one who have healer combos are Britt and Ralf or Kirk and Tyr (which you absolutely want to do because Tyr and Kirk have secret CG). Maxing the tree choice doesn't really affect the combos anyway, and what you lost in the chapter didn't come from maxing the tree, but absolutely from losing most of the characters.
Cause I've only played Seidr and Valkrye, I can tell you very much the reason why Seidr is better is because you get a quick solve for one of the puzzle (Not the behemoth one, and don't do that until they fix it because you'll miss a cg) and many unique dialogues, not the combat in the slightest. I can't say for Alf, but I am sure I won't enjoy the combat more than I did with Valkrye because I despise combat with Alf.
I totally agree with your point with the crit chance, but the chapter didn't need a lot of farming items or admiration because you don't get bonus from job anyway, and because I usually already maxed MOST of the characters (because my Valkrye tend to have high masculine)
