Mostly I'd say go ahead and outsource with some amount of quality control. DKCR was given to Retro, but Miyamoto and others were checking in making sure the game was fun.
If any first party outsources a game, they should make sure innovation happens. Retro was able to create superb atmosphere with Primes, aswell as a fresh take on 2D platforming with DKCR.
On a rare occasion I'd say no. If the vision of the series is uniqely belonging to the first party, outsourcing might not work. Pikmin 3 has yet to reach its potential, and likely Miyamoto's vision of the series.







