Dontuberme I remember a video(fully charged?) where platinum was doubtful that the switch would work because b4nny's influence on the match would be lessened. However, b4nny seemed to be just as game changing and formidable as ever. The same thing could be said of when platinum played switched to demo and when enigma played roamer.
B4nny is a very, very good caller. That's probably the greatest asset a demo can bring a team (any combo class really.) The question was not about DM or anything like that, but whether or not xalox would be as formidable in his calling, while in actuality the choice was made to improve comms on the flank. Similarly, plat on demo puts him in effectively the same seat with calls, the same can be said about enigma on roamer. When it comes to that, it's always about anticipating what the enemy team will do and making a counter strategy. If you want good examples on those in both defensive and offensive positions, you can easily watch demos, find a good match (you know, 5-4's etc etc), then examine what both teams are doing, how they react to changes in the other team and how successful those strategies are.
I'd say for the most part, watch your STV's. Note your mistakes, fix them and think about what could happen and you'll get better in a few seasons.