Re: "Allowing the Germans to take the French naval assets would make that goal a lot harder to achieve."

No. It would have "made that goal impossible to achieve". It would have meant certain defeat.

Naval superiority was the British trump card — the only reason they were “in with a chance” at all. If the French Fleet fell into Axis hands, thus tipping naval superiority in favour of the Axis, the British would have been doomed.

That is why it was imperative that the French Fleet be totally removed from the Med - either by repatriation (which the French refused to do) or by destruction. There could be no half-measures. The devious Darlan and the puffed-up and huffy French Admiral at Mers El Kébir failed to grasp this.

Fortunately it was a completely different story with the French squadron at Alexandria (which consisted of the battleship 'Lorraine', heavy cruiser 'Suffren' and three modern light cruisers). This was dealt-with successfully via negotiations - because the two commanders—Admirals René-Emile Godfroy and Andrew Cunningham—were on good personal terms.