I don't see how it has all that much verisimilitude when it's applied so unevenly, though. Either persistent effects require spellcasters to concentrate on them, or they don't. 5e can't seem to decide which it is.
Mage is like, "Wow, that summoned hammer thing is powerful, do you have to concentrate on that?"
- "Nah, I just cast it and it sticks around for a minute without further attention."
- "Wait, really? But I just made some little dancing lights, and I have to keep concentrating on those..."
Cleric is like, "Wow, that armor spell you cast is even better than my Shield of Faith (well, kinda), do you have to concentrate on that?"
- "Nah, I just cast it and it lasts eight hours without me ever thinking about it again, lol"
- "WAT."
In the case of Shield of Faith, the only reason that I can think of for it to be concentration is because SOF paired with Bless would be a bit rigged.
You become less likely to get hit from spells and attacks, give an attack bonus to you and your allies, and get a bonus to keep concentration if you do get hit.
I get what you're saying about inconsistency with concentration across spells, but my gripe is more with the power imbalance between the spells themselves. If there's a concentration tag on it, it has to and should be able to compete with all the other conc. spells of that level.
If for instance, SOF applied to as many targets as Bless, there would be different scenarios where one spell would be better than another. You would have to make a choice between better defense against attacks vs more accuracy and spell defense. As is though, Bless gives 3 or more targets an accuracy and spell defense boost, to SOF's 1 target gets a defense boost.
I never prepare SOF because 9 times out of 10, Bless is just a better choice.
