He brings his proof that MOSHIACH can come from the dead from the fact that the gemora says doniel can be moshiach.
The abbarbanel holds that moshiach can come from the dead using this gemora, (meaning he doesn’t learn the gemora the way you were learning it till now, that it can only be doniel but rather he learns, that from the fact that doniel can be moshiach we can use the same logic for anyone else that passes away) and that why he has no problem with the yerushalmi.
You have to remember the abarbanel is trying to answer a question that someone might have regarding this story. So he says the question is not a question, because we already see such a thing in sanhedrin that moshiach can come from the dead.
In your words you can say the abarbanel is arguing with rashi.