Very likely - scab resistance does not mean scab immune and the presence of a heavily infected tree nearby could certainly create problems.

Maybe try this one. But I'd cut down the second existing tree anyway if it were mine because it looked bad - why do you want to hang on to it?

The U.S. National Arboretum presents Malus 'Adirondack', an elegant testament to the versatility and landscape value of the ornamental crabapple

http://www.usna.usda.gov/Newintro/adirond1.html

That's really gorgeous, thank you Embo!