Buffy the Vampire Slayer
Angel...a Vampire
none of the 2 would make any sense in your case.
while its true I prefer Angel over Buffy. but Buffy S1-3 are still my favorite.
its like this:
Btvs S1-3>Ats>Btvs S4-7
I said I prefer Angel, because when I compare, I don't count Btvs S1-3, Cordelia & Angel were regulars. Cordelia carried a small deal of the show. Angel however, carried the entire storyline with Buffy. S2 was pretty much about the 2 of them & their relationship.
after S3, Buffy started to go downhill, I love S4 & 5, it was still the same show, it still had its charm, & still one of my favorite. but it started getting bad by S6, & S7 pretty much sucked. S7 was like the first Season of the show "Tales of the Slayers", if it existed, of course.
when Angel ended, it still had potential for many Seasons to come, if JW had been patient & didn't demand an early renewal, the show might be on its 11th Season by now. Angel S5's ratings were very high from what I've heard.
anyway, I disagree with your point, both shows cannot carry themselves without the Action.