This survey makes it seem like more Muslims are radicalized than you seem to think based on what you wrote
https://www.gatestoneinstitute.org/7861/british-muslims-surv...
https://www.gatestoneinstitute.org/7861/british-muslims-surv...
Maybe take a look at the number of muslim civilians killed in Somalia, Iraq, Syria, Pakistan, Bangladesh by the number of Muslim extremists. It's a lot more than you seem to think.
I never claimed that radical Muslims don't want to kill other Muslims. In fact the Sunni and Shiite conflict probably killed more Muslims than non-Muslims.