Switching Flea and Tick Meds every other month

Does anyone now if topical flea and tick meds like Advantix and Frontline are ment to be used every month so the specific drug they use can build in the dogs system. I was thinking about getting tw meds and switching every month. One, so the dog is exposed to less of a single drug and two so the fleas and ticks around them don't build any ammunities. I was thinking about using both Advantix II and Frontline, I would likely use them every other month or maybe use Advantix in the heavier mosquitoe months.