Disclaimer: I'm still yet new to the game. This is all from what I've read and theorized based on game systems.

It seems a lot of the problem lies with the initial plan for party design not being followed through on. I believe there's two tank slots in an 8 person party for a reason and why one tank was the defense oriented with less damage tank and one was the offense oriented squishier tank. Tank swapping was intended to be a key mechanic, the high defense oriented tank would handle phases of fights where heavy damage that the more offensively oriented tank couldn't handle effectively. It was probably designed for something like start phase (mild to moderate damage tanked by offense oriented tank) high damage phase (switch to the highly defensive tank) and so forth until the end of the fight. However, that presents the issue of not having that offensively oriented tank be able to perform evenly so they equalized defensive abilities.

In trying to equalize defense capability they essentially took from the defense specialized tank the one thing that made them better in those situations. I think the best way to fix paladin would be to match current aggro output to the other tanks but also to boost their defense notably and return to that time where that high defense was good to have. I believe DRK was also designed in mind only instead of offensively and defensively it was split between physical and magical damage, where the DRK would handle magical damage and the PLD would handle physical. However, because of how well warriors preform and how paladins lack damage output in this DPS race metagame that niche was closed off as well.

I believe Alexander Savage is really just a data collection point for rebalancing classes and regaining that synergy and as we learn more about patch 3.1 that will become clearer.