What's "scale" is relative, but there's no doubt whatsoever that the AerodromeRC kit is much, much, MUCH more scale than the BUSA kit. The BUSA kit might even be described as "cartoon-scale" in comparison.

Of course, being more scale could also mean that the AerodromeRC model might be a bit harder to fly, though by all accounts it's a good flier. I'm with Greg (and Matz) though, that since you already have the BUSA kit, you should just go ahead and build it (quickly) with minimal design changes, for example, replacing the slab sides. No matter what you do, there's no real way to turn this sow's ear into a silk purse. So just have fun with it.