How do we know that Pattons approach would have worked? I guess people see some similarities to Operation Cobra and assume Patton did it before and can again but there are no similiarities. The Western Allies never broke through and achieved an operational breakthrough if big german Panzer forces were available for defense. Not a single time at least in Europe. Most major armored attacks in Normandy resulted in minor gains with huge tank losses for the allies. Goodwood, Epsom, Tractable, Totalize et cetera. The later operations against pretty weak armored forces. Operation Cobra was an exception because of the force ratios achieved at this particular point. During Cobra the ratios for tanks was 12 - 1 same ratios were achieved for artillery, airsupport and to some extend infantry.

The situation in the Bulge was vastly different despite slowly pulling back and shifting troops to the east for new offensives the build up of the Wehrmacht was pretty big. The amount of tanks availabe would have had serious impact in defensive situations. The Western Front was generally very low on tanks after Normandy because no reinforcements were send during mid 1944 and after that the priority was the Eastern Front. The Battle of the Bulge was an exception here and its highly unlikely that a major armoured offensive against the still present German tank force would be wise. The German tanks were pulled back anyways and moved to Hungary for Spring Awakening. It should also be noted that Operation Cobra was not the success it was because of its design but rather the reaction of the Wehrmacht.