Siting cultivars susceptible to the same thing apart from each other?

I've ordered 8 different varieties of bare root apple trees, and while most of them are resistant to all of the "standard" diseases, a few of the more specialty varieties are susceptible to apple cedar rust.  When siting these trees, should I be separating the rust susceptible trees with trees that are resistant, or does it even matter, considering how far apple cedar rust can travel?

I don't think it would matter since the spores can travel very far.  Look into JADAM Sulfur as a treatment. I use it for Cedar Quince Rust on my Pears.

 separating the rust susceptible trees with trees that are resistant

Possibly the influence from the roots of resistant trees and through the mycorrhizal network would improve the their resistance.  I covered my peach trees to combat peach leaf curl but they have become increasingly resistant perhaps by exchange with nearby plum trees that are very resistant.  

Hans Quistorff wrote:

 separating the rust susceptible trees with trees that are resistant

Possibly the influence from the roots of resistant trees and through the mycorrhizal network would improve the their resistance.  I covered my peach trees to combat peach leaf curl but they have become increasingly resistant perhaps by exchange with nearby plum trees that are very resistant.  

Interesting concept.  Since they're all grafted on the same 2 rootstocks, it seems unlikely that the resistance will transfer, but it certainly doesn't hurt!  Thanks!