Backwards,
Hope this helps:
The C isn't really a larger aircraft than the A - it needs larger wings to land more slowly, is all. And larger tails to control itself at lower speeds. The main weight drivers are the hundreds of lumps of extra metal inside the airframe to handle launch and recovery loads. Oh, and the landing gear.
You are right that naval aircraft (generally) get some benefit from their tougher structure - but it's still a weight penalty whichever way you look at it. In a fast jet combat aircraft, weight is just a bad thing, as the F-35 programme found out to its cost a few years back.
The discussion on weight differentials for F-35 and Rafale is really interesting - it does look as if the French have achieved a near miracle in limiting carrier ops 'scar' weight to 1000 lbs or so. Or, their assumptions for carrier loads are off.
And to respond - properly integrating aircraft ops with ship ops to get best effect is a complex challenge. The RN don't claim it, they state it. That's because it's a fact. Ask the USN, the French, the Chinese, the Indians.......
Best Regards as ever
Engines