Reasonable buff to war

[ReiMakoto]

Talking about Stonecrusher, not the megalith. HG doesn't last long enough to last through the entire Stonecrusher as a WAR must burn cooldowns on the first hit then HG it meaning healers have to make sure you are topped off before the first hit and then heal you up right as stonecrusher ends. You try to HG just stonecrusher... you are dead by the third hit. Its more work than all the other tanks need.
Megalith... why not just share it? If you are invulning the stonecrushers (as you should be) you only get the benifit of WAR to holmgang a megalith when your tanks are going to have all their CDs up. Yeah IF the WAR is targetted by the megalith then they can holmgang it but that's a 50/50 shot and again, why do you need to invuln that? The only one where its nice is right before final phase to save an extra cooldown... but you don't need to because rampart is up for the final megalith. So again... why are you invuling megalith? There is no reason to. You aren't saving the healers any extra healing as they are just going to throw a regend on the OT and OGCD heal the MT.
Seriously I have cleared Titan with a WAR and my healers HAAAAATED it. When you have planned out a fight entirely on your cooldowns and when to heal tanks they realize when the stonecrushers are coming up they don't need to top you off, instead they could save their healers for post tankbuster to top off (unless it was me as a PLD). WAR throws a wrench entirely at this practice and forces healers for stonecrusher to stop and heal the war. Nascent flash? Why are you even using it to help your GNB? They should be just fine without your 'help' its only 10% mitigation, just reprisal the megalith you are mitigated more damage that way because its effecting BOTH tanks not just 1 or... where is the feint from your DPS? Seriously the only thing fient effects in this fight is the shared TB and auto attacks (yes Tumalts is classified as magical by the game... for some reason). You never need to HG or even immune a single megalith as you shouldn't. They don't hit that hard when mitigated or planned out mitigation decently.

Unless all my runs have just had incredible coincidence, megalith targets the person on top aggro, so we do a pattern of Holgang -> Bolide the Stonecrushers, then Holm -> Bolide the megaliths. As to why you'd invuln it, I'd say convenience, my WAR holms the first one and pops just enough mitigation to take the hit after the knockback and just live, then holmgang -> bene. Whilst I'm popping enough mitigation that i can just get passively topped off by aura/ raidwide healing so the healer barely have to touch us the whole interaction

Also for stonecrusher, I heart of stone the first hit on my WAR then he just holmgangs the other 2 hits no problem, the first stonecrush happens so close to the start of the fight the WAR's basically on full health anyway and the healers have the rescource to top off / ogcd shield the first hit then bene up.