Would you rather have a random element instead of a pre-determined outcome for the breach element as it was in the game that you have played?
I would rather have a CQC inside the building where one could some control over the out come.
For instance an SMG unit would perform better than bolt action unit.
The feature, as it was in the SP, was meant to give the US faction a choice for finding solutions using an advantageous ability as an alternative to chucking grenades. There is an element of risk to the ability after all, and it is very similar to units flanking an MG that is not in a building.
Imo abilities are a good way to designed the game (and they should be more, for instance for SMG troops) but not ones with that "I press a button I win a fight" logic.