Well any excuse to get a new tank going is fine by me, so from that POV yes you need a new tank
J/k, but seriously the rainbow shark is ideally kept in a 55g, as he'll outgrow your 32g.
Now the rest of your tank, I'd not say it overstocked, I just find the mixture and amounts unlucky if I may be that strait fwd with you!?
Kribensis I'd house as a couple, thou they will get territorial when breeding I think.
White clouds I'd house as school only, so 8 and up would be ideal and the same for the Cardinals.
But stocking up to these amounts I'd not do in a 32g.
Personally if you can (financially) I'd get a 55g set up and house the Rainbow, Barbs and 2-3 Kribensis in there (and add some other proper stock as your pocket allows it).
Then have the 32g with 8-10 cardinals and 8-10 White Clouds, and because I love them, I'd personally add some Cory Cats to the 32g then
Hey YOU ask, hope I don't get beat now