A Spitfire or Hurricane at +6¼ psi and 3000 rpm will only give about 880 bhp at sea level.
With a 2 position prop you might not be able to even get 3000 rpm, in which case, fewer rpm means less power again.
The DB601A's 1 minute rating is 1100 PS at sea level, ie about 1085 bhp; its 5 minute rating was 1025 PS, or about 1011 bhp.
So you really don't want to be caught on the deck in an RAF fighter if the Merlin dragging it through the sky is burning 87 octane fuel, especially if it doesn't have a constant speed prop.
OTOH, if you have 100 octane fuel and a constant speed prop then the Merlin III will give something like 1200 bhp at +12 psi boost and 3000 rpm; the Merlin XII's takeoff rating was 1175 bhp at +12½ psi at 3000 rpm - but it had a supercharger gear ratio of 9.089 to get a higher FTH and make better use of 100 octane fuel. Therefore the Merlin III with a supercharger gear ratio of 8.588 would actually develop more bhp on the deck because it's using less power to drive its supercharger; 1200-1250 bhp is a reasonable estimate.
I think that in all probability if/when we get 100 octane Spitfires and Hurricanes that the 110 will have a rather hard time of it on the deck.
Unfortunately it's not possible to fight at high altitude with CEM at the moment; but if we could then the extra power available to the Merlin at its FTH would make quite a big difference to the performance picture.
So I think that at the moment it's all about waiting for patches to fix the high altitude bug and to give the RAF 100 octane fuel. I don't think that the Bf-110's performance is excessive, though I obviously haven't been able to test properly at altitude, and there are still quite a lot of general performance questions to be answered (see my
test flying thread).