best low tier generals? (skill-wise)

Hull is definitely a great early choice, as an infantry general to fight delaying actions or generally just be a meatshield can really help in the first two campaigns (a better meatshield with lower output could also be Rowland). Dumouriez or Hull (or Rowland) should be a first buy, and after that Kutaisov or Sokolnicki or Marmont as artillery to help w/ the output side of things, and last I'd go with the one you hadn't bought from the first buy, inf or cav.

Then I'd focus on a tier 2 art general (regrouping tier 1 into the tier 2 replacement), and then cav, and finally if you want an inf general (Dobeln is best, in my opinion). Golitsyn or Sulkowski make great last slot fillers from tier 2, and thats that. Now go get some princesses!