As further support for my observation that BATMAN and THE SPIRIT are rough equals despite differences in their respective levels of humor and pathos, I'll put forth a parallel example, drawn from comedy.
Consider two genuinely-comical comic strips, both with some degree of critical fame, BARNABY, first published in 1942, and POPEYE, "born" in 1929 in the strip THIMBLE THEATRE, which had kicked around about ten years before the one-eyed sailor took it over.
I don't think that anyone would have a problem labelling these two comic strips as "comedies." One might have to do a lot of tweaking to Northrop Frye's theory of mythoi in order to see them both as pursuing the theme of anagnorisis, but that's a theoretical problem for another time. Both strips are certainly dominated by the narrative aim of being funny, just as THE SPIRIT and BATMAN are arguably dominated by the narrative aim of being exciting.
Now, let us assume that all right-minded people agree that both BARNABY and POPEYE fully deserve their reputations for being good comedies, however different the types of humor may be. One may like BARNABY's gentle spoofery more than Popeye's slapstick violence, or vice versa, but in theory one can agree that each fulfills its comic mythos admirably.
Now, because POPEYE does use slapstick violence, it does have a narrative element in common with SPIRIT and BATMAN that might cause one to associate the former with the latter two in terms of its *mythos.* POPEYE does sometimes incorporate elements of the adventure-mythos, with emphasis on the agon, which can take the form of Popeye's many battles with big ugly brutes (of which his cartoon nemesis Bluto was just one minor example) or his duels with menaces like the Sea Hag. Despite these elements, by my calculation the strip was never dominantly about adventure, but it could be termed correctly a "comedy with adventure elements."
Now, it's my stated position that to the extent that the Golden Age BATMAN ever attempted any dramatic stories (which wasn't often), they were probably never as well executed as those of Eisner's SPIRIT. But saying that doesn't eliminate the accomplishments of both features as adventure-mythoi.
However, if one were to say "superior pathos makes THE SPIRIT the better work," then by the same token one would have to say that POPEYE is better than BARNABY because POPEYE had better agon-fights.
I've only read one collection of BARNABY, and I don't think it had any fights in it whatsoever. But if in BARNABY's ten years anything like a fight ever happened in the strip, and if the quality of that one fight was inferior to those in POPEYE, then POPEYE would be the superior work because it didn't realize that narrative element as well as POPEYE did.
Unless, of course, one takes the position that the narrative elements of the agon simply don't matter.
And in the world of unsupportable beliefs, I suppose anything is possible.