What's this guy got that's shoots so far?
Ok, my advice:
Start as close as possible... If you get the first placed unit, and it's heavy support, stick a talose as close as you can to opponent deployment.. If it's a quarters match, then right at your center corner.. This does 2 things, it causes him to bunch his army together, and it affords you the scenery cover in the more central parts of the map..
Take a few warrior squads on foot with a wych squad behind.. SPREAD THEM OUT... 2" apart, and keep them that way as they move closer... It's scary looking and will draw lots of fire...
The rest of the army should attack on one side, and one side only.. CC blocks LOS.. So do that.. Reavers moving 24" farward will also cause a huge distraction..
And finally... 3 raiders, 1 ravager, 4 reavers, and 3 hellions in one turn? you either play huge armies, or your opponent is splitting up his fire.. If his devistators shoot, they MUST SHOOT AT ONLY ONE UNIT.. they can NOT split fire to more than one unit...
For you, I would try to tie up the devistator squads with reavers or block LOS with CC to other units between them and your ravager.. Try to get the larger CC oriented squads with your ravager first, then if your reavers get killed off in CC, deal with the devastators.. Only take 6 incubi to save points, and get them into combat ASAP.. if they get shot down, hide behind the foot shloging warriors..