Not the best idea but can really depend on your controller.... Many cheap controllers are very noisy and the only way to determine that is to try it...
You should not have issues with either of those wire.....I took Maine Sails advice and got the Genasun gv-10 controller. The cabling in question is mostly the Seatalk-ng for one gps antenna, and I believe a smaller diameter (maybe rg-8?) for the passive gps antenna going to the ais unit. I can separate them if it's at all an issue..