No, it wouldn't.

The idea that early christianity "copied" other cults is not a terrible hypothesis and is worth exploring. But the problem with mythicism is occams razor.

When you look at the New Testament as a historical artifact and not as divine scripture, what you have are a vareity of sources on the developing practices, beliefs, and mythologies of a first century cult worshipping a messiah claimant named Jesus who got crucified. How did this cult come to be? While there's great reason to doubt the exact narrative the New Testament itself tells; all the best explanations come down to there being, in some way, an actual Jewish messiah claimant named Jesus who got crucified. You milage may vary, but you've got to do a whole lot more explaining away to say a bunch of peasant Jews invented the entire thing by peicing together myths from other cults.