Vanheim has a great utility forger disciple in the eldest dwarf who could make rings, D boosters, A boosters and staves by himself.
The forger bonus doesn't really matter. You can forge the same things with another chassis too (and Vanheim can do A boosters and staves natively), what rituals (or rarely, combat spells) you can cast is just as important. Sage isn't just about the research bonus, but starting with S is good if you want the rings.
No its fairly massive when you want one devoted disciple to do it all. Means -1 for ring forging so you can do it with S4 instead of S5, count the points. D boosters for D3, A boosters for A3, staves for E3A3.
You can do a A3E3S4D3N4 dwarf. He can forge two rings, elemental staves, all air, death boosters and moonvine bracelet/treelord staff.
Again - you don't need the dwarf to do any AE Elemental staff shit, Vanheim already has it covered. Why would you waste your disciple points / time to forge those?
N2 would be enough for the dwarf in any case, to get Treelords Staff (borderline useless item tho, so who cares), allowing him to buy say, F1W1B1 crosspaths. That would be a bit better, but still not quite optimal. E2 would be enough for the staff also btw.
You have to think - why are boosters important? Why is a specific expensive booster important (not talking about 10gem massproduced shit obviously)? You want to get to specific spell X, usually. When will you need that spell? You reach most booster's path requirements eventually anyway if you want (especially so as a team), if you can and want to forge RoS. Will you need a specific booster, say Skullface, before RoS? Why? I'm not saying you can't have a reason but you do need one. You don't always want to make a booster even if you can, either.
A dwarf may be able to forge boosters a bit more and earlier than a human, but if he wears them he's only getting even in that path to the human that way.
The dwarf is borderline better at forging, but loses out on all the other uses of a rainbow - sitesearching, research, rituals. You can't just think that eventually you can forge X, Y, Z. What are you doing with him early on, and what then? Thinking about the turn to turn activity is probably more important than what singular big things you can reach.
Also Vanheim overall is a poor nation for a rainbow meant for forging, due to having the slowest research in the team. A sage could be justified in order to turn that around, but a Dwarf can't do it.
For example a F3A1W3E1S6D1N2B1 or F3A2W3E1S5D2N2B1 sage could forge p. much any reasonable thing I'd need - the big boosters are reachable once you have RoS and summons, Elemental Staff (FW) reached with cheapo boosters, you can forge Robe of the Sea right off the bat (ok, needs gems somewhere), summon F and W mages, can do Rune Smashers, so on and so forth. And ofc a good researcher, which early on counts the most.
If you just want certain boosters, you can do that with a combat chassis. Say, a S5D4 Lich to make rings and Skullface for you. Who can use most of his time fighting. A Lich like that would be a fun Mind Dueler actually...
Question is, is any of that worth it over a combat Disciple in the first year? If we survive it definitely is mid-late game. I expect this to be a low diplomacy game(for Dominions), and that makes things more risky imo.
Remember that any boosters still need a user. An SC disciple is not just his chassis but also his paths -they don't have any best before date either, can cast and forge just as well as a rainbow though with a narrower selection.
Johannes, why no love for soul contracts? Too expensive? Too annoying to waste paths on?
Even with just 2-3 in games, the devils pile up. Set it and forget it, and before you know there's 30 devils, ready to raid any province, kill SCs, support armies. Admittedly it's hard to calculate cost effectiveness.
They cost a lot of slaves. When are you hunting for those slaves? If you're worrying about staying alive, Contracts are the last thing you should be doing. Use those mages to research or summon troops you can use right away.
