No, the martial arcanist feature is unique to the abjurant champion, and not found on any divine prestige class. I cannot actually prove this statement without listing the full details of every prestige class feature in the game—but it is 100% certain, thanks to @forrestfire, who has actually read every prestige class feature in the game (yes, even those) and has told me unequivocally that abjurant champion is the only class that has the ability to treat caster level equal to base attack bonus. (I, myself, could only be almost entirely sure.)
Do note the Practiced Spellcaster feat found in Complete Arcane or Complete Divine—that can effectively make up to four levels that don’t progress your caster level start to progress it. That is good enough for the overwhelming majority of situations.
Further, a divine variant on the abjurant champion is not only easy to imagine—as irbian’s fine answer points out, Complete Mage explicitly suggests the possibility. It also suggests that a psionic variant could work, and I can personally attest that it can, having recently finished a campaign playing a “psychostatic champion” as I called it. I have not played with a divine one, but compared to the arcane or psionic versions, a “divine champion” is quite a bit simpler and arguably less powerful:
Unlike psionic powers, divine spells are categorized as abjuration spells when that is appropriate, allowing abjurant champion features to apply directly. This is much more complicated for psionics, which don’t have any category analogous to abjuration.¹
Unlike arcanists, divine spellcasters
- don’t suffer from arcane spell failure
- usually get armor proficiency
- often get ¾ BAB by default
- may well be able to cast divine power if that BAB isn’t good enough
That means (most) divine spellcasters have better armor and BAB than most arcane spellcasters, so the abjurant champion’s advantages in these area are relatively less valuable. (Much of this comparison also applies to a lot of psionics: 2-3 apply to psions, and 3-4 apply to wilders. 4 applies to pretty much everything that doesn’t use the cleric spell list.)
These make a divine adaptation of abjurant champion easier than a psionic one, and arguably less powerful than the official arcane version. There’s a synergy between divine power and martial
arcanist “divinist,” but it’s very minor and only of benefit to less-powerful characters.
- For my own character, I just went through all the psionic powers and wrote out a list of which ones were compatible with the champion’s abilities.