The simple reason Clover could beat any penguin individually and all four as a group is she can win against an entire pack of fossa while all four penguins were going to die fighting the same fossa. Clover is my favorite loser at life but she is stronger and more skilled than skipper enough where she easily has fun destroying animals that skipper would lose against. Clover, a tiny lemur, accomplishes the same effect as A LION
Regarding who's more experienced, it's not accurate to say Skipper has more experience than her, even if you believe he's older. Clover has been surviving in the wild and fighting relentlessly against deadly predators designed to kill her during all the years Skipper was living safely in a zoo. That's the definition of having more experience.
Clover in her free time boxes large mammals for fun every week, and she takes them out with one punch. Meanwhile, Skipper in a cage match against a large mammal was such a threatening dilemma for him to survive that it was the plot of a whole episode.