It's strange that we have some job specific actions which have been replaced with a single role specific version (Rampart) and others which are identical but job specific (Sentinel/Vengeance/Shadow Wall/Nebula). Likewise, they replaced most of the old raidwide mitigation abilities with Reprisal in Stormblood, and then slowly proceeded to add back tank specific alternatives over the past two expansions. I don't think that the four people who are on job design duty for SE have really thought any of this through.

I think the ideal is to find a unifying theme for each job, and find an alternate approach for achieving the same end result. Failing that, having alternate animations for the same actions at least gives the jobs a bit of unique flavour.