1) How is it "merit" is strictly about genetic variation, rather than a combination of said genetic ability and a record of the use of it (achievement).
2) How is it that equality is strictly about starting position, rather than starting position resource allocation protection? One can have a meritocracy in which resource allocation is not about more-to better. It can in fact be about responsibility and accountability being greater. Not saying I agree with this, it is just a hole in the argument.
3) Resource distribution need not be 0-sum. There can in fact be more than 2 categories of "mine" and "not mine". There can be categories such as "available to everyone", "available to no one", and variations on "available to some". [1]
4) deserves is always and strictly a moral argument. There is no justification of deserves that doesn't at some point refer directly to axioms (morals). Therefore we again get to assumptions that need be discussed.
[1] Here in lies all the interesting stuff. Interplay between "some people get access" and "mine" categories of resources are where all discussions like this are really happening. How you define "some people get access" really can change the end result of "mine" for various actors. Similarly, "everyone gets access", in reality, is very tricky. For instance you could claim, and be mostly right, that everyone gets access to computers (via public libraries etc). Yet, not everyone gets access to training in effective computer use - that is reserved for "some people get access", where the rules are 'has enough money for proper training' (aka defining access rules on how much is already in your "mine" resoures). It is a complicated interplay.