There is almost no relationship between duelling and MA fighting except in regard to the most fundamental aspects of performing ACMs in general.
When duelling there are rules and restrictions that limit choice and freedom of action from the hanger to the merge. So, initiative tends to remain rather balanced and the longer the fight, the more restricted your options become as E states degrade, it is a game of move and counter-move. Duels are largely determined by the proper selection of those moves and counter-moves and their efficient execution relative to your opponent. Outside of that finite realm there are relatively few decisions to be made based upon almost perfect information until the final outcome. It's a fairly straightforward process.
MA fighting, on the other-hand, is an endless stream of open ended decisions that must constantly be made and acted upon. Unlike in duels, the conditions are both infinitely varied and dynamically changing with both known and unknown mitigating variables. The initiative swings wildly back and forth between yourself and your opponent(s) and unlike duelling your decisions are intrinsically based upon only partial and imperfect information. This chaotic environment produces a plethora of decisions that you must make throughout with subsequent results that are unique to ones' own mental disposition, approach to the game and relative plane performance considerations. No two people will enter a fray and perform the exact same maneuvers, make the same decisions and actions or think of the fight in the same way.
In summary, the primary focus of duels leans toward the physical stick-work of flying itself, wheras MA fighting's focus is primarily on mental acuity and decision making.