Zapdos doesn't really check stuff like lando-i, especially CM. Zapdos also cannot check or counter zard-y in the slightest, and loses to specs keldeo too, so I really don't see the comparison here ?_?
Haze is sorta irrelevant (screw bp) but Defog is a pretty big asset that clears up a moveslot for skarm, and unlike Zapdos, Mantine isn't total garbage at defogging. Ok Zap isn't taht bad but Zap is pretty shit there are SO many stealth rockers that Zapdos straight up loses to or cannot beat; out of all the rock setters in the tier it literally only forces out ferrothorn, skarm, and....pinsir. Mantine actually threatens garchomp and other stuff with a potential scald burn.
Finally, there aren't that many electric types in the tier in the first place, and every one of them except thundurus is outstandingly weak. Megaman and raikou pose no threat to stall whatsoever, i mean forget chansey, quagsire is enough to stop a large majority of them. Rotom-W is annoying, but its annoying to a lot of stall teams anyway, and its not like rotom-w has an incredibly easy time switching in between toxic and scald burns. Besides, if its restochesto, then that's even nicer cuz pain split imo is what makes rotom-w annoying in the first place. So its really not too difficult to just nail the rotom-w with a well timed toxic and call it a day.
In terms of synergy, venu tran actually fits pretty well with this guy, or the otehr way around. Mons like keld, cahr-y, and lando which break venu tran are stopped cleanly by mantine, and a nice fwg core is thus formed. Definitely not too much of a hindrance to teammates.
So yeah mantine is a stronk check to char-y, keldeo, and Lando-i, so consider for analysis :]