Trimming the hair on the top third of the ears will help them stand if they're a bit floppy.
As to it affecting the dog's balance.....what a load of rubbish!!
Good grief, my Skyes with their big, frilly , butterfly ears would be staggering around like drunks
As for poor little Papillons......perhaps that's why Edna always carries Tootsie around on Emmerdale eh?