Going sword and shield is a very questionable decision in FFXI. Really only PLD does it because Aegis is so strong or WAR with blurred shield+1 for a fencer build on cloudsplitter when physical damage isn't ideal. The biggest reason why no one else will do it is it makes capping delay reduction extremely difficult. If you have capped equipment and magical haste, then you are at 68.75% delay reduction. You need another 11.25% from either 11~ job haste or 36 dual wield to get to 80%, which is where all the other jobs in the game that hit stuff should be.

This is foremost a DPS problem for anyone wearing a shield, but it also translates into an enmity issue if you are trying to tank. The less damage you do, the less enmity you generate. Doing more damage equals more enmity. So ideally, anyone tanking would want to cap their delay to deal more damage for enmity purposes.

The only current solution to this is bring a DNC main for 10% haste samba and dont use enspells that will block them. That's very unfortunate for PLD because enlight 2 is good for making up accuracy that they need because they generally itemize for tanking stats. RDM would lose additional damage, which is less of a consideration because their enspells aren't that good imo. WAR doesn't really get affected in any negative way.

The Proposal: Make Shield Mastery give 11~ job haste when a shield is equipped. OR Make shield mastery act like dual wield to reduce 1h delay when you have a shield equipped. The more generous and simple option being the 11 job haste.

So if we go with the first proposal, PLD get to keep enlight 2 for accuracy and cap delay reduction so they do more auto attack damage for more enmity. Because the delay between attacks is less without any sacrifice to DPS in any way, this will make the enmity gain more consistent. They also get shorter recasts on their spells as a bonus. WAR gets a better Fencer build, which is what the gifts, relic, and new JSE neck are all pushing. It's easy to think SE is trying to support this. RDM gets the same benefits as PLD in addition to not being as heavily penalized for picking a mage sub to do aoe sleeps and stuns instead of a dual wield sub for damage.

If a job such as BRD, BST, BLU, GEO, SCH, or WHM wants to /PLD, they would also get the 11 job haste so they could enjoy using a Genmei/Genbu Shield for a durability, delay reduction, and recast boost (sorry BST, Tatami/Pallas or maybe Absorbing Shield for you). Not to mention access to sentinel, shield bash, cure 3, and a little auto refresh.

None of that seems overboard because there are better subjobs for damage or utility for all of those jobs. This would just be the subjob for defense/recasts that doesn't completely sink your melee damage, if that is something you care about. BRD/WHM vs BRD/PLD, for example, would be a choice between Cure 4 and -na spells over Cure 3 with better delay reductions and Sentinel for oh shit moments.

IF that was all considered too much, we could look at the other proposal. Making Shield Mastery mimic Dual Wield for the delay reduction. Dual Wield wouldn't affect recasts on PLD+RDM or /PLD. RDM would top out at 15% delay reduction from Shield Mastery 2 mimicing Dual Wield 2 and would need 21 dual wield in gear to hit cap which could be done. WAR would get 25% and only need to wear Emicho Gauntlets+1 or one of the good dual wield belts to cap which fits the general theme of WAR getting nice things. PLD would get 30% base at lvl 99 and the full 36 dual wield when it get it's last shield mastery gift from JPs. Thus fitting PLD as being the best job with a shield and also making it so that PLDs don't have to itemize for capped delay reduction so they can focus on tanking.

If you wanted to make this path more attractive, you can add the block bonus TP gain for the shield mastery level on each hit. Master PLD would get +55 extra TP per hit. WAR would get +30 TP and RDM would get +20 TP. None of this would be affected by Store TP.

I dont think many people would look at /PLD for 10% dual wield reduction with a shield and have to make up an additional 26 dual wield to cap as an attractive option. Maybe BRDs or BLU if they could set dual wield themselves and it would use their value instead.

As it stands right now, PLD < RUN because it doesn't deal enough damage and lacks RUNs party utility. Making up some damage and having better enmity generation would make it so you don't prefer a PLD only against physically punishing enemies. WAR having better Fencer builds would really round them out, as WAR is generally the resident weapons master, without buffing their 2H damage at all. RDM being so dependant on /DNC or /NIN for doing damage has always been frustrating and any real RDM would welcome this change because they are used to having to gear extensively for what they are doing. You could more easily pick /BLM or /SCH for mage utility without complete back lining yourself.