I wouldn't keep them together, just to be safe. You have to be pretty careful mixing frogs and newts, since some are poisonous, and some will eat the other. Do you have frogs already, or are you planning to get them? I have Fire-Bellied toads--they're pretty cool, although a lot of work!
It sounds like paddletail newts you are talking about and they should definitely not be mixed with little african dwarf clawed frogs cos they stay really small and paddletails get big (about 7-8 inch) and will eat them. Fire belly newts stay smaller though (about 4-5 inch) and they will get along better with your little frogs. If you were wanting to keep frogs with paddletails you could try the albino frog as they too get big (roughly the size of the palm of your hand) though you'd have to watch they get very greedy and newts can be slow eaters and the paddletails may not be able to keep up! The benefit of these two frogs is that they are purely aquatic and can be kept with fish, whereas newts need a half filled tank to enable them to come up for air and they can poison fish. Though remember the albino's will eat anything smaller than them! You'll have a lot of luck with the African Dwarfs though, they are excellent little things to watch and won't bother each other or fish. Enjoy your new addition!