I'm running my first Campaign, and am sort of using the main story from Land of Fire and Ice, and am running into problems with Galdramen.
Neither the Graugachan, nor the Learned Mathematicians seem appropriate to the spirirt magic of the Gadramen as presented in LoFaI. I have Hedge Magic, Ancient Magic, Rival Magic, RoP: M and F, and can't find anything that I could shoehorn into this.
I deeply suspect that what I want is to adapt the Sahir from The Cradle and the Crescent, but the other story I am in (as a player) is very probably using the fluff in that, and I don't want spoliers.
Does anyone have any suggestions about what to do?
I think the easiest way to reproduce the "flavour" of Galdramen from LoFaI is just to give them an ability that mechanically works like Hermetic Sihr from HoH:S's Hermetic Sahirs, stipulating that instead of djinni it affects landsvaettir. Then give the landsvaettir the powers you want, using the various RoP:M/F/I books.
Personally, I think that all the "flavour" you may have extracted for your galdramen from reading up tC&tC's Sahirs is already in HoH:S's Sihr; tC&tC's Sahirs have many more powers (so reading the mechanics of Hermetic Sihr from HoH:S won't spoil anything) but they don't really match Galdramen well.
Ezzelino's idea certainly works. You can also use plain Summoners from ROP:I as an alternative. You could achieve all the effects listed for galdramen if you take the secondary pack of abilities of summoners (bind & command) and tone them down a bit. I would stay out of Ablating. The other 2 toned down a bit could be magical abilities without much problems.
If you consider Landvaettir to be Faerie, their abilities can also be simulated with the RoP:F powers. These are extremely flexible to mix and match different abilities, so I am sure you can find an effective combo there. ROP:F gives me headaches (and I do not like ArM5 take on faeries) so I do not use the, but I recall them being easy to manipulate into whatever tradition you like mixing them up.
Use an equivalent to Sihr from HoH:S but define it as affecting "landsvaettir" (including the Faerie "alfar") instead of "jinn". Additional powers such as shapeshifting and hamfarir etc can be additional Virtues (see Hedge Magic for some ideas on this). There's a suggested example Irish folk tradition, the Corrugineach, who use the same mechanics as Hermetic sahir and would provide a precedent.
"Schooled" Galdramen would fir with Learned Magicians, perhaps with some elementalist (Theurgy) powers.