I'm young and still very new to the circuit, but as part of a collegiate team with less experience than most of the teams in the circuit, I think we find it very difficult to teach brand new dancers formations without markers, as they're still focusing on learning the many elements & technique of the dance form itself. It becomes hard for them to mentally juggle formations solely relative to the rest of the team while still keeping the moves as true to form as they possibly can.
For what it's worth, of all the vids I've seen of the best teams on the circuit, I can say that I do think a performance without stage markers is an impressive feat of team cohesion. At a higher level of dance, a performance without markers is very executable, and probably should be preferred, but I'm keeping teams like mine in my thoughts when I say that markers act as a form of training wheels for dancers who haven't fully internalized how to do most moves in bhangra, keeping them a bit more focused.
Sorry if i'm just beating a dead horse here. I saw the thread get bumped, read through it, and wanted to offer my perspective. Let me know what you think.
Ishaan