It's not so much the ravager you should be worried about, it's your transports without saturation they will be in big trouble. And you won't be able to count on them getting anywhere.
How many point are you playing at?
What's in your transports?
I find I can get away with six vehicles at 1500pts, I have tried less, but the units just end up getting stranded (one of the reasons I dropped the wyches and now use warriors as they don't need their transport to function). The talos and the ravager will both draw fire, but you can expect to lose transports early on, so investing in upgrades like splinter racks, night shields, flicker fields and so on might not be worth while (as those venoms/raiders will die).
I think you could get away with it as long as you don't have close combat units in those transports and you are playing at 1500pts anything more and you will need more saturation. Reavers do not count in this case as anti infantry fire is far more effective against them so I would never count on your opponent firing his AT at them.
Hope that helps.
_________________
Latest Report: BR4: The Repugnant Ramblers Vs Imperial Knights - 1250pts
Pragmatic Realspace Raider Series
“Even the Black Buzzards thought highly of him, and those maniacs were renowned for hating everyone.” - Tantalus, by Braden Campbell