Everywhere I have lived and flown, it was long-standing practice among DPEs that if you had an instrument rating, it "automatically" met the requirement for the 10 hours of instrument training for your Commercial. After all, it's not a stretch to assume that that requirement is in there specifically because you can get a Commercial without having an instrument rating, therefore some instrument training is important for a CP. If an instrument rating WAS a prerequisite for the Commercial, there would be no reason to have the instrument training requirement as part of the Commercial experience requirements.
The Chief Counsel COULD have just said "if you have an instrument rating in the same category, that meets the requirements of 61.129", and I would have been perfectly content, and I think that would have been perfectly reasonable, and in my opinion, in accordance with what I view as the spirit and intent of the regulations.
But they didn't word it that way, so now we're left with situations like this:
Which is just ridiculous, to have applicants and CFIs re-accomplishing training and/or negotiating with DPEs on what's good enough. This is not the same as "Ok to solo". The instrument-rated pilot has been formally tested on instrument skills by a designated representative of the FAA and deemed to be competent. It should suffice.