Spirit Guide is pretty ridiculously strong thanks to getting to change its Wandering Spirit every day. That kind of versatility on top of the already really powerful Oracle base is pretty crazy already.
i am not picing it for versatility but im making a plant based character and will only stick to the wood spirit since i also have the wood mysterie the spell list would overlap thou and I would like it to be a bit more efficient at least
Sadly, no. They both modify class skills. Otherwise it would be the best combo ever, with Paizo rules at least.
If you use 3PP rules, combining Spirit Guide with Mixed-Mystery Oracle (Rite Publishing) would be a real party!
By RAW, no, you cannot combine them since they both "modify" the mystery class skills. Should it be allowed? Definitely since Dual Cursed literally removes the class skills making any modifications from other archetypes irrelevant.