SGE's shield GCD is closer, but not exactly the same.
Eucrasia takes 1 sec to recast, and then 1.5 sec recast on the actual Diagnosis. For AST's Noct Aspected Benefic, it's instant from the beginning, which allows 2 oGCDs to be weaved in. SGE's GCD allows one because you can't fit an oGCD in Eucrasia's 1 sec recast with it's 0.7 sec animation lock. You can fit one in Eucrasia Diagnosis though since it's 1.5 sec recast, but you also have to note because there's around a ~1.7 sec to 2 secs before your heal/shield registers on the player due to animation lock, it's like an invisible cast timer.