What evidence do you have that the Klan, which counted its membership in the millions in its heyday? Or FARC, which controls a significant part of Colombia? Or ETA, which has killed over 800 people through terrorist acts? Or the IRA, which killed over 1500-1800 people and wounded an estimated 6000 police and soldiers and 14,000 civilians?
Tell their victims that these "much smaller groups" weren't important enough for you to recognize them as serious terrorists.
Islamofascist terrorists and their supporters and enablers surpass them all by a long shot.