I don't think they're strong enough precedent, tbh. I wouldn't call Hanke really tall when compared to Balotelli & especially Haaland. Also, as I remember it, he played a very mobile & flexible forward role under Favre, which I think is something of a basic requirement. He was at least as much a supporting player as a goalscorer (8 goals in his very good 11/12 season, Reus did the heavy lifting in that department).
De Camargo was okay-ish (and a decent overall footballer), but he only scored 13 goals (9 in BL) in more than two seasons under Favre. Not a blueprint for Haaland either, imo. I'd still say Balotelli is the only successful precedent of a CF similar to Haaland's build over a longer time. We'll see what happens.
Your assessment of the Favre situation is very plausible. I hope he and the team still manage a turnaround in consistency, but it's less than certain.