Just walking myself through the different 'disciplines' in the Omnium and my thoughts would be:
1) Scratch race - Cav has to be in with a chance so top 3/win or if a fast race, then he could be as low as 10 or worse
2) Individual Pursuit - not Cav's strongest but he will have done a lot of pursuit training to try and race in the team pursuit and although a different skill set, it is still a pursuit so top 5
3) The (brilliant) Elimination race - again top 3 here simply due to his ability to explode high watts over short periods even when knackered
4) TT - 1km is short enough for Cav to top 5 again here but this one may trip him up? He is after all more of a racer than a disciplined TT'er?
5) Flying Lap - top 3? Or a win? 250m is not far off his perfect distance for his aero and sprint?
6) Points race - he is bu66ered! I think by here, he will be leading or top 3. This will 'encourage' the whole field to effectively mark him out of contention. If he tries anything, he will be shut down. He won't chase everything as I expect a fast pace generally to stifle too many attacks and 'laps'. Having said that, didn't he steal a march in a 'recent' Madison?? Despite being marked 'out of contention'?
Anyway, that's my prediction and I will take great pleasure in eating my hat when my punditry is shown up for what it is - nonsense