What about creating an ACTUAL Dark Knight?

[Ultimatecalibur]

Also in FFIV, if you look at Cecil's stats as a Dark Knight, he's actually pretty low in HP and stamina. It just so happens that several of your teammates are mages so they are weaker than you. Just compare his stats to Kain's or Yang's.

Dark Knight Cecil's Stats are actually superior to Kain's for the level range that they appear together (and only really start exceeding DK Cecil's at the levels where you should have Paladin Cecil). Yang's stats are inflated to make up for Yang's inferior equipment.