The problem isn't primarily one of tank size or resists: it's dictors' horrible combination of a cruiser-sized sig and cruiser-sized top speeds with frigate tanks. It's really the speed and sigs that need tweaking more than EHP (although a decent-sized EHP increase to keep pace with the tank-creep that's been pervasive among small ships since the tiericide started would also be welcome).

What they'd do if they actually wanted to make dictors into viable combat hulls rather than bubble-and-run mobiles would be to increase EHP by ~20-25% (via raw HP or resists-- I don't think it would matter that much, although at least with resists you could theoretically keep dictors up using remote reps for small gang fights), increase the top speeds across the board such that nano-fit dictors can manage 3-3.5km/s while MWDing, and shrink their base sig radii down to 45-50 instead of the absurd ~75 they're sitting at right now.

Essentially, dictors should really resemble frigates more than they do cruisers: small tanks, high mobility (which helps them mitigate damage AND do their job of grabbing initial tackles / decloaks better) and small sigs.

On a somewhat-related note, I find it hilarious that interceptors-- ships that aren't forced to find themselves inside bubbles constantly and which are the best-equipped ships in the game in terms of their ability to rapidly burn out of bubbles they do find themselves in-- are getting bubble immunity, while dictors-- relatively slow, tankless ships that are forced to drop themselves in the middle of a 20km bubble just to do their jobs-- are stuck in their own bubbles. If anything it should be dictors that are bubble immune (allowing them to not kill themselves by tackling and allowing them to bypass "defensive" bubbles and use their own bubbles on hostile fleets to, you know, do their jobs. But what do I know, I've just been doing small-gang PvP in nullsec since 2007.

Basically these changes do next to nothing to address the fact that the combat abilities of interdictors have become absolutely farcical. Between the speed nerf that destroyed their ability to speed tank damage and the Tiericide-induced power creep that has significantly buffed what seems like every other ship class in the game, the only things that an interdictor can actually fight these days are stealth bombers (assuming they don't have a buddy in another bomber waiting to decloak and bomb you, that is), some scanning frigates (beware ye battle-Helios, however), and some industrial ships. Yeah: some industrial ships: some of those mining barges with 40k ehp and the ability to field drones will probably wreck you. Combat frigates, T1 destroyers, cruisers, some interceptors, all assault frigs, cruisers, battlecruisers, and battleships will all completely wreck you if you hang around decloaked long enough to get locked. Our game-designer buddies are acting like they're doing us some kind of big favor by "bringing all other dictors up to the level of the Sabre." Great, except that there's almost nothing that the existing inferior dictors can't fight that a Sabre can. The Sabre is mostly a bubble-and-run machine too, unless you really like losing Sabres...

I'm honestly incredibly disappointed by these changes: while I haven't been enthusiastic about most of the changes of the Tiericide Age, most of them have been things I could work with or around. With interdictors CCP are passing up their best (probably only) opportunity to fix a class that has been seriously underwhelming for years now, and that has only been further emasculated by the tiericide buffs to other small ships. Instead of doing anything to actually make dictors viable and fun ships, CCP are playing it safe by calling the Sabre "good enough" and balancing all the other dictors against it. This is really, obviously not going to do anything to improve the state of dictor-piloting, since anyone with a clue who uses their dictor outside intentionally-suicidal fleet tackling runs has already trained for a Sabre anyway. The only reason people continue to fly Sabres is that dictors are functionally indispensable, and the Sabre is the least-bad of the bunch. That doesn't mean the Sabre (or your new lineup of dictors balanced around it) will be in a good place when your changes go through, and you know it. Shame on you, CCP. I expected more from a team of designers who allegedly spent years playing this game.