If worst comes to worst and we don't have enough players, I know you have some great tasks planned out for all roles. Maybe cut a role from belonging to any particular player, and instead have teams share that role's tasks among the whole team? That way we'd have the least damage to the cool tasks you want to put into play.
Problem with your suggestion is that it can possibly ruin the functionality and co-operative feeling of our combo tasks...
We have already prepared every task for every role for every round. Like you said, I wouldn't like to see the hard work Nae put into most tasks going to waste, but I still prefer dropping a team instead of a role. Brawl#3 had gone well with just 5 teams, so I don't find why Brawl#4 is going to suffer from that worst-case scenario.
That said, it was a quite well-thought suggestion, Elk, and I would like to see Nae's opinion for it.
Keep up any future suggestions coming, you guys!