I would not advise to execute the two at the same operation. The main reason is, during a merge conflict, you will need to resolve it before committing. So when the first operation fails, you are left out with a state that requires another commit anyway.
If you need to do this, to simplify the ideal case workflow, at least create a script to handle the conflictual case and revert back to the starting revision, so that the user can merge and commit normally. But using a simple alias will cause you more trouble than help you, in the end.