Honestly, I only started really focusing on it this season to get that stupid FR and Stasis Fragments Done (FYI...they can't fix Shiver Strike fast enough; trying to get Powered Stasis Melee Kills with a melee so slow that even a Dreg can dodge you is absolutely rediculous), but the way it is now, I can see why they are worried about Heavy Ammo Economy. Well, I can kind of see why...but one of the biggest things that needs to be done is honestly making Hunters and Warlocks simply take more damage than a Titan (it needs to be said...there is no reason why a Warlock and Hunter can have as high of damage resistance as a person encased in armor; it boggles the mind), simply because of how insane they can be as an invader.
A Shadebinder invader is literally your worst nightmare with a fully charged super. Hunters can already dodge and have a movement advantage while using Truth to be as cheap as they possibly can be during an invasion....being able to down them with a rocket or 2 should be the least of what a team can expect. Maybe a Titan being an invader wouldn't be so "Isn't he cute?" as it is now if they were as hard to bring down as at least a Taken Phalanx blocker. My Titan gets kills as an invader, but I usually only go in when I have a super charged or enough Special and Heavy ammo I can burn people down. I think making it so a Titan can shrug off damage much better than a Warlock or Hunter further defines the differences in the classes as well as fixes any "heavy ammo economy" issues...meaning they think we get too much because invaders basically bludgeon you with it because they have damage reduction and an overshield.
Suddenly Warlock invaders are a threat due to the sheer damage potential the class has or the CC power of it's Stasis super. Hunters would be a threat due to their inherent mobility and flitting nature. And Titans would be the equivalent of the Rhino running down Madison Avenue (sorry, still salty I'll never get to play a really good Spider-Man game on my Xbox XD); the inherent threat would be in how much damage they could absorb before you could bring them down.