It might have been, provided you had inexhaustible resources. The Reich didn't. They Germans only got involved because the Italians were getting their clocks clean bu the British. It was a reflexive reaction, not a plan.
There was no way to move sufficient force to the theater, so the Heer had to send penny packets until sufficient forces were built up. They would then attack, rapidly use up their supplies and vehicles and be forced to withdraw, even if the offensive was not actively defeated. Even if one can justify the Western Desert (and IMO, it can't be justified) the decision to try to hold French North Africa was, simply put, asinine.
Put as clearly as possible, would it have been better to have an additional 300,000 Heer troops, 4,000 additional Luftwaffe aircraft, and around 1,000 tanks/assault guns holding the Don in place of the Croats, Romanians and Italians (all of whom were ill equipped, especially in heavy weapons) when Uranus kicked off or have them in North Africa cut off for any possible evac and resupply?