I can't talk about the Piranhas deck, but since I am an avid Skeelz user, I can say a thing or two about the latter. First of all you might want to change Manfred to Greem when she is not banned. The possibilty of being poisoned will make many persons overpill, and thus she can be a usefull bluff, especially on the first round. Aside from that, your deck is the same as mine, except I switched Sandro with Chiara Cr . I can say that this deck works pretty good for ELO.
Piranas deck looks okay, aside Raeth over Sting or Lizbeth/Bloodh/Selma/Dalhia Cr and Hawkins over Baba and Sting.
As for the Skeelz deck, Greem is out of the question as she is permabanned. If Cley and Liam work for you great, but if not Belle is the best substitute for Liam, unless you want to swap him and Manfred to some of the Skeelz 3* (There's a lot to pick from). Same for Cley, but if the higher damage works, keep him around. Manfred in the deck is a bit tricky, but Belgosi or Jay could fill the 4* gap if the confidence abilities clash too badly. The 5* card is purely a matter of preference. Tomas does a good enough job at it.