Psylo and Nahema are decent... "decent". There are better four stars like Niva and Eggman, and Buba in a mono. The only deck I'd see those cards is DM extended. All three stars that Jungo have are good except for probably Dagouba. All two stars in Jungo except for Somba are good. Troompah and Askai tie for the best Jungo 5 star, (in my opinion) then, Ongh.
Get Radek. He's cheap, and a very good card. I'd use him over Psylo anyday. (Rodney is good too but Mindy is better at what she does). If you don't have the clintz for Troompah, consider using Boohma, he's pretty good in mono.
Gerald is "decent" too if you're low on budget.
Well Max this is difficult to answer as you did not specify what format you are looking to build a deck for. Let me know what format you are making one for and I'll help you out.
The cards you have are good/OK for play, most useless is Psylo, not because SoA isnt great to have - but because Psylo basically have nothing else for 4*....
Buba is sweet always for mono Jungo.
Most importantly you need now attack aiding cards to make your life a little easier. Here your choise limited:
5* - Askai, Troompah
4* - none
3* - Radek, Rodney and as last resort (or for survivor) Boohma
2* - Mindy
And finally DR cards give you manouver space. I dont recommend Niva because she is predicatable - but Pegh is extremely useful.
And then there is Jean - the new card. You get the cheap SoA in great shell for the starcost.