If you change 1,2,3,4 into A,B,C,D - you're still counting. You're just using different symbols to do it.
Take a moment longer to think about it and you realize that 1,2,3,4 are also just symbols - potentially raw counting does not require these symbols at all.
So ABCD is unlikely to make life easier for the subject of this story.
We are in agreement then. I'm not saying it would make things easier, it's just convention. Being a lifelong musician, I will admit that it's so internalized in me, I never have to count or even think about numbers in any way, unless I'm counting some foreign complicated time signature. Honestly I think the tabla guys got it right with their syllabic mnemonics.
Take a moment longer to think about it and you realize that 1,2,3,4 are also just symbols - potentially raw counting does not require these symbols at all.
So ABCD is unlikely to make life easier for the subject of this story.