Far from it, but I've had a lot of team-signed balls that were much more faded than yours. Just calling them as I see them, and no guarantees on authenticity
Generally, if you can narrow down the teams/years, you can look at the rosters on baseball-reference.com for the ones you can only make out a few letters of and narrow it down by process of elimination. Sometimes all you can make out is a first and last letter, but when you see the name in the list, you have that "aha" moment and the rest becomes clearer. Then you can compare to known signatures of those players to double check and be sure. That's my usual process anyway.
Sometimes using a black light can help to pick out the really faded ones as well.
Good luck with the rest!