three is a pretty good number of lines of credit to have at your age;
do you plan on applying for anymore cards within the next year or two or are you content with the freedom/slate/blue cash combo?
when I was that age I only had two prime cards and a few store cards that was never used and subsequently closed because I was young and dumb (to apply for those, esp victoria secret..asking for my social I shoulda known better)
that was Amex and a MC. they were perfectly fine for me and they auto increased my CL as time passed, though that was a different era
In your shoes I most likely would just keep those three cards, and close the two, unless there was another card i would want, then i would wait until I applied for that card and have it open to close the two
for a twenty year old, having those three cards is pretty good, might just want to use them and grow