It would definitely be a marriage of convenience, just like Reagan Bush.
However, Reagan had an awful exit strategy by leaving things with Bush in ‘92. Reagan should’ve dumped Bush in ‘88 for someone more conservative and solid. Yeah, it’s all in retrospect.
So to not repeat history, if Trump goes with Kasich in 2016 just to get those dominoes falling starting in Ohio on election day, hopefully Trump will dump Kasich in 2020 for someone more conservative, after he has already set the country back on solid ground, and he doesn’t need to play such electoral college shenanigans to win again for one more term.
How could Reagan dump Bush in 1988? Reagan wasn’t running. Bush was running for re-election in 1992.