There is minimal literature available though, What level of fighter was the research conducted on? Was it a controlled study? I've not seen much that actually has peer reviewed research on elite fighters in this area, however I would be more than open to it if its out there! Do you have the reference?
If the fighters were sub elite how do we really use that? They might be using their anaerobic pathways more so than aerobic because they have to and aerobic not developed fully! So we cannot just assume that it is the anaerobic pathways that predominate.
All the higher level pro fighters I've trained have had a high aerobic capacity but at the end of the day the best way to get results is to coach/develop the athlete. By that i mean if you have an athlete who is very poor aerobically but extremely powerful anaerobically I would suggest that athlete needs to improve his/her aerobic capacity to be able to train for longer durations and maintain technique under fatigue.
If they have excellent aerobic fitness but poor anaerobic then do the opposite and most will be somewhere in the middle. Obviously it needs to be specific to obtain best transfer.
Using MMA tabatas or equivalent develops all the systems, and is also specific preparation which can be made even more specific by studying your fighters movement patterns and working on these in the circuit. This seems to produce good transfer for me.
The baseline level of fitness is important and I go more into this in the webinar earlier this year. How you obtain it is down to the fighter coach but I would suggest that aerobic intervals are used.
2012 Webinar
For me its simple, get em strong and powerful then increase the durations that force and technique can be produced with intensity in a reverse periodised fashion with the end goal of 3-5x5 minute rounds in mind. I don't think i've talked about energy systems in a long time and apart from the odd guy who is poor aerobically on some of the baseline measures, I don't tend to stress "energy system development" very much at all.
As one of the athletic development greats Vern Gambetta puts it "Build it first, then learn to endure it".