but on a air to ground role the jncubus is by far better, you can tank more forge guns round then the python and ..... it also handles much better than the python

I disagree with you here. I have run the math and only in a "perfect storm" is Gallente better at damage absorption. They can tank the same number of forge hits as caldari. In some fits you have more health left after hit two, but hit 3 is often fatal for both ships, less if they are not fitted with duel hardeners. Ill post up the damage charts to support my statements. The charts do not support better tank ability for Gallente. As for handling better, they are smoother but they are much slower.

I use jovians, it makes up the gap to an extent. As for the rest of your post, my experience disagrees, depending on your fit a 2 shot from a forge gun often knocks you down into armour, if your fit is light on tanking mods it can take you into armour burn as well, that's nearly always fatal for pythons, on an incubus on the other hand the fact that most fits will be carrying a repper means that's not an issue, and the modules longer lasting nature means you can take the second hit and rep past it. I've had armour dropships survive ridiculous amounts of damage, falling as low as 0 armour in some cases and survive, shield ones tend to die much quicker when they get hit by forge guns in my experience.

Caldari ships gets an inherent resistance to swarms I know, and that gives them better survivability to them, but asides from that and a higher base acceleration gallente has all the advantages. Just because it has better numbers on paper doesn't mean that it performs better in game.

ditch the heat sink for a light shield extender, survivabilty is more important than a minor offensive gain