Rust_Lord, the interdictor may have been tougher in the books and the flight sim but in this particular game the interdictor is not made for combat. The interdictor shouldn't have to fight either.
The interdictor can enter combat and survive without a scratch on it's armor if used correctly...
-Star destroyers are extremly weak to proton torpedoes and if in the vicinity of an interdicor becomes much tougher to destroy. The Star Destroyer along with it's fighters can defend the interdictor form any attacks made by enemy cruisers or fighters.
-Most rebel and consortium players prefer a bombing run tactic by rushing with B-wings and Skiprays to quickly deactivate the shield systems or hangar bay, but an interdictor defeats this strategy. Keep Tie defenders and TIE phantoms nearby to pick off any fighters that move into range.
-High level space stations are equipped with numerous pronton torpedo HP's forcing the player to keep his heavy cruisers out of range, consequently leaving his fighters to the mercy of the enemy corvettes. Using an interdictor solves this problem. The heavy cruisers will defend the interdictor from attack in addition to being safeguarded by fighters.
Phantoms and Scouts may not be necessary for victory in a battle but they certainly help. I like knowing where my enemy is without sacrificing my TIE interceptors or TIE Defenders to corvettes (they may be trivial losses but I don't see the point in wasting fighters needlessly). One maurader cruiser or corvette can wipe out an entire recon force of TIE Defenders and TIE Interceptors without any difficulty preventing any recon mission from being a success. The Phantom however has no problems. Besides, sending in TIE Interceptors and TIE Defenders reveals your position and makes it easier for the enemy to know where to send their cruisers and fighters.
I agree with about pop cap space though, that's why I send in only one Phantom squadron or one Scout squadron. That takes up only one pop cap space.
I think the primary use of the DT phase 3 is guard duty, not assault. Mobility makes no difference when defending. I use them to patrol choke points on the map and to guard my AT-ATs from flanking. They are the best vehicle destroyers in the game as well thanks to their rockets. Phase 3's are extremly effective defensive units if stationed near a repair station and an MDU with an EM field generator.
"You will pay the price for your lack of vision!" - Palpatine