Well I would agree that both are very nasty, however… fascism doesn’t necessarily involve many of the traits of Islamism. Islamism you and I both perceive as a genuine threat.
i think we both also agree, that we should differentiate with Islam as a religion and the political movement that is in the process of hijacking that faith.
If we fight Islam instead of Islamism, we lose a very important ally… the moderate Muslim. We will drive more of the now moderate or secular Muslims into Islamism.
After all, by politically fighting their religion, we are politicizing that religion and it is the politicized Islam that we (need to) fear. From that perspective I like your terminology, but it still distracts from the true problem.