That sounded utterly preposterous at first. But if I saw a bog standard looking rain team and the opponent didn't start with politoed, which does happen if they fear you have something that can OHKO it in your lead spot. Then they just used water absorb politoed and bulky DD Kingdra and SubSeed Ludicolo and Spinner Kabutops.Is running Water Absorb Politoad even worth considering (for mind games?)
If you don't bring in them in, the ability is impossible to know: given enough pokemon on your team that appear to be suited for rain, your opponent will put two and two together and try to kill Politoad and change the weather (this works for other weathers too btw) to something that "doesn't" benefit you, namely sand. You could basically engineer teams that appear to be weather teams at first glance, but are meant to fool teams and take them by surprise while still functioning fine.
It would be the greatest mindgame of all time.