What could DRK have learned from FFXI?

[Absimiliard]

Sorry but heavy armor and higher hp is pretty much what made characters tanks in those days. Pretty much every character that would be considered a "tank" in the current time would have superior hp and physical defense but have vulnerability to magic. (Spellcasters could almost always no sell any spell they were hit with even with their limited amounts of hp).

Cecil also had garbage HP scaling as a dark knight. The only part of your criteria he seems to meet is his heavy armor, but even his defense had some pretty poor scaling beyond what the armor itself gave him.

Pretty much. There were only 2 real types of characters in those days: Frontliners/Vanguards and Backliners/Rearguards. Vanguards were pretty much expected to take hits while dealing damage with low/no resource cost while Rearguards were pretty much expected to either heal or deal massive damage by expending resources.

Enemies did not have a discernibly higher chance to target the front row with their physical attacks or magical attacks. The only differences between being front row or back row were your physical damage taken and physical damage dealt. Back row characters dealt and sustained half the normal amount, while front row characters inflicted and sustained the normal amount. There were of course some exceptions.

Next point: Kain exists. Kain could and did equip what would be termed "heavy armor" as well, including a shield He specialized in dealing large amounts of single target damage via his jump command. He also had excellent HP scaling and decent defense scaling. His magic defense was a bit lackluster.

Anywho, I think we might've derailed this thread enough at this point. Guess I better write something on topic.

FFXI's DRK was never actually intended to tank. It could acquire hate due to the ridiculous enmity multipliers SE put on its abilities. The problem is that these very same abilities actually hamstrung its defenses.