"Really yes that would be fairer. However the government aren't up for sharing in the Med crossings. And it would certainly mean an increase in migrant numbers."
Would it necessarily? Migrant numbers would have be negioated, however there are countries whose woking populations are decreasing due to migration. It is sense to send people where the population is decreasing. (Whether the cause is low birth rate or migration.) It makes sense to look at the density of population in particular regions of the EU (excluding unhabitable land).
en.wikipedia.org/wiki/Population_decline
Wealthier countries/ regions that take less migrants should shoulder more of the financial cost of managing ayslum seekers.
Poland, Estonia, Lativa are safe countries. They might not be wealthy, but it would be safe. Poland would benefit from an injection of cash from wealthy countries. Countries who are reluctant to stomp up cash could take a higher quota of migrants.