Ok, the deal with bridgeing is this, yes ox and primo don't suppress your hpta that much. But, if you already have your hpta suppressed, they will not let your body recover.
So, you want to get off the primo, do the clomid, and be reasonable sure that your 'balls are back online.' Otherwise, you would be wasting clomid, and further suppressing your hpta for however long you were going to do the primo. And if that runs into (*I think*) week 14 or so, it will take awhile for your hpta to come back. And that would defeat the whole purpose of a bridge.