An A class sailing in a A class competition is an a A class , an A class racing in a mixed competition ( like on your local club night where the majority of racing takes place), has to have a handicap rating, at a rough guide I think this is 1.01 under SCHRS

Add a 2.0 blade jib and reduce the main to 10.94 and the handicap drops to 0.883. An all conquering Tornado with probably 2.5 times the sail area is 0.935, so you can see the 2 sail A really does not stand much chance of development outside of the A class.

Now we all know that on the water in top hands the Uni will beat the sloop. Oops the handicap system gets that one sooooooooooooo wrong and that is the problem with light weight boats/jibs/ weight. But this very real problem (m which is stopping boat development in my opinion )is another thread and not what we should be discussing here on this particular thread.