Well, in addition to the block rate you mentioned, a Paladin shield also carries a huge chunk of armor. It’s why it was mentioned in the video; it’s a straight up reduction in incoming physical damage that helps passively. So Paladin does actually have a bit of extra protection that the other two tanks don’t have. As mentioned in the video, they suffer under magical damage a bit more, but that’s what gives them the advantage over DRK.
WAR’s survival ability over DRK is that, while they take more damage from every hit, they have a LOT more HP to soak it with. As I said a while back there, the biggest problem is that a healer has to heal that damage, but it is, overall, less of a WAR’s HP. DRK, for example, reduces incoming damage by 20%. WARs have an additional 25% HP. In the end, that gives WARs a 5% extra window of damage toward zero at the cost of a little extra mana to keep them healed.
In the end, DRK really isn’t very complicated. Their DPS rotation is relatively straightforward, and mana isn’t at all difficult to manage. You’ll spend more focus managing wrath stacks and what to do with them than you’d ever spend on mana. Normally, it might be a pain in the ass, I’d agree, but DRKs, because of their exceptionally high DPS in tank stance, have remarkable enmity generation. More than that, they essentially can use mana to give them even MORE gas on their threat. So all that is to be done is build up a threat lead and cycle your mana generating abilities (which isn’t difficult, since that combo is also your main DPS rotation).
In the end, I’d say that DRK has a slightly higher skill window simply because the turnover is fairly long. A lot of your cooldowns are absolutely necessary, but also on some weird timers. Dumping moves mid GCD actually isn’t too terribly bad, it’s your spike damage forcing you to choose whether you use a precious CD now and don’t have it later. You can screw yourself over quite a way down the road by not adequately handling your cooldowns.
By the same token, I feel like WAR resource generation is actually a lot more difficult than DRK. DRK is actually pretty easy to maintain mana on, where WAR makes it only too easy to burn TP and get it back slowly. And, of course, the only way to even get a modicum of TP back on WAR that I know of requires you to shift out of Defiance and wait for the 10 second CD for it to come back at least, sometimes not an option since AOE is what drains it so fast in the first place. WAR’s biggest advantage seems to be the opposite of DRK, their CDs aren’t as necessary and one of them, Inner Beast, can be available relatively often if you know how to just wait a few beats for a tankbuster. In all, WAR is on a very short turnover, and you don’t have to be afraid of firing a CD (save for Berzerk, which, unless you’ve got a good healer that times the cleanse for the pacification, means you’re out of DPS and, as you say, you need to stuff DPS in that window).
As it stands, I tend to “main” WAR, simply because most endgame content are single-boss trial fights and in a random group a WAR can compensate for a lot of bad play from elsewhere (the self-heals, easily accessible mitigations, etc.). I run on a DRK for dungeons, especially, since the resource management is so much easier and you don’t have to worry at all if you’re firing up Blood Price in an AOE situation.
I don’t use PLD as much simply because the DPS potential of a PLD is lower than the other classes, either WAR in Deliverance or DRK. Most often, they tend to get slapped in front of the boss simply because they’re the least effective DPSers, not because they’re the most effective tank.
Results vary, though. I’ve found that the old maxim applies that the flavor of the month attracts poor performance when everyone switches to it. So while WAR potential isn’t I think especially high, lots of random WARs you see in groups have no idea how to reach it but have heard that you can. That’s led, over the course of Heavensward, to stack a lot of tanks in the WAR class and brought the average skill level way down. And, as you say, the one thing WAR DPS potential can be is twitchy. Like DRK survivability, you have to align some stars to max it, and people fail that a lot. I end up out-DPSing a lot of WAR OTs on my DRK without leaving Grit, which shouldn’t happen….