I am writing a paper where the proofs involve more than one field of mathematics. Call them fields X and Y for simplification. This is not very unusual, but I think it may confuse the editor in the following sense:

There are several motivations for the paper coming from both fields X and Y. However, all technically hard parts in the proofs belong to field X.

So, in my opinion, it would be best to get at least 2 referees, at least one of them from field X (but another one from field Y would be great, at least to give comments regarding the motivation).

While I am not the first one to write about the problem my paper attacks, it is still a rather new problem, and an editor possibly will not have the right "feeling" about what kind of expertise is required for working on this problem.

Even more confusing: Previous work on this problem has been done through field Z, which is certainly not my approach (people from field Z will have to struggle quite a bit with the technical parts of my paper, as I had to struggle with reading their work).

My contribution in this paper is "generalization, theory building, solving some open problems stated by others, stating new open problems". But there is another contribution - I give new motivation which applies also to previous work (not done by me), but went unnoticed.

I would like to communicate to the editor the information regarding what kind of mathematicians I think should review my paper (when I submit it). However, I am afraid it may come out as very rude: Not only I am telling him how to do his work, I am telling him how to judge my own work! Yet, if I were the editor (I am young and not an editor anywhere), I think I would appreciate the information that "this is how the author thinks I should do my work".

Should I communicate any of this information to the editor? What part of it? If coming out as rude was not be an issue at all, I would send a list of possible reviewers explaining why they are good for the job in my opinion.