Sounds very similar to approaches we've taken with C++ with a team that largely didn't have C++ experience(~15 devs, 2-3 C++ "experts", I use the term losely). Also similar to the approach DropBox said they use with their cross-platform C++ code form a talk a while back.

In cases like this I feel like convention does a good job of keeping a codebase from spawling out into using every feature of the language.