Not my pilpulim, sources from seforim:
In Sefer Pada Es Avraham by the Gaon R’ Avraham Palagi (Mareches Shin, Os 19, Daf 22c) writes: ” To give a male the name “Simcha” is consistent with the psukim, but to do the opposite, to give a female this male name, one must wonder if it is permitted, since it is placing a male garment on a female (lo yiyeh kli gever al isha), because it causes confusuin among the genders.”
Although we find women named Simcha, it is a male name and as quotes, one must wonder if it is permitted – as this sefer writes.
As I wrote earlier, there were many gedolim, such as student of Rashi, Baalei Tosfos, the Or Samech etc. that were called Simcha. It is a man’s name that people. for whatever unknown reason, also use for women (not the other way around).To assert that it is a woman’s name and not a man’s name is factually incorrect.