Allowing Ogrovs to hit Titans would defeat the purpose of Titans completely. They'd basically just be a starbase that can phase jump, with no greater or lesser survivability than the units we got years ago in Entrenchment. And if you're the Advent, you already have starbases that can move (albeit not phase jump), so it's even more of a yawner.
Titans are meant to be downright durable, which they are for the most part (unless fighting another Titan). They're tough as nails, and nothing out there counters them in the sense that they can break its back with a few volleys like the Ogrovs can a starbase.
That's the point.
If you're going to take that away from Titans, you may as well just add them as another capital ship type, make them smaller to scale with the other capital ship types, get rid of the titan-specific factory, and just call it capital ship type #7.
But that wouldn't be as cool, would it?
What the game needs is a way to impair Titans. Make it so that their raw durability and firepower is unmatched and can almost carry a fleet on its own, but on the other hand, make it so that they have an achilles' heel that can pin them down, keep them from being effective, and eventually (with persistence) cause them to die. But in general, it should not be possible for a Titan to flat out die unless it's either completely unsupported by friendly fleets against a massive enemy fleet, or if it's battling another Titan. But the primary way to destroy a Titan should be to hit it with your own Titan.
Still, it should be possible for a faction that hasn't yet built their Titan to scare off an enemy titan without it being an unstoppable force that takes over their entire empire. For this role I think we need to buff corvettes against titans, at least enough to disable the best of their effectiveness and cause their offensive potential to be substantially weakened. This would encourage / force the player controlling the titan to have to retreat, which is about as much of a victory as you can expect against a Titan if you don't have one of your own.