totally not recommended Alf unless you plan to cheat. I don't have to cheat ever with Seidr and can handle every single thing at any difficulty without cheating at all. it's by far the easiest one. The only one I have to cheat was Alf because they are that difficult at ch.4 non-civilwar (I will say, I know I can finish non-civilwar ch.4 without cheating, but the time and the expense especially the pain was way beyond my comfort level). I don't have this problem with Valk because they are good at combat, granted at early chapter you're somewhat relying on crit to trigger combos, but they are nowhere as horrendous as Alf in combat. Alf definitely shines in production, but if I am honest, in all of my 12++ playthroughs, all it did was making creating stuffs easier, which I hardly find that relevant. I know it's weird seeing how crafting is the main bulk of this game, but that's just my experience playing all three classes in these different playthroughs. Alf definitely is the worse class and totally not for beginner. That being said, as I said before somewhere in the forum, if you have a good luck, Combat in Alf would be the easiest because it is that reliant on crit from your medic drone, once you through that hurdle, you're good. It's just for me, for that to happen, I usually had to empty my power first cause I have rotten luck.
The only reason why I crashed out on Seidr in ch.9 is simply because of a bug with Seidr taking Valk skill. I redid ch.8 which used to have the same bug, and I breezed through the combats in no time.