Shy, 1st off, droppit pronounced like draw-pit (fast) muppet pronounced like muh-pit (fast)
So it has that aw/uh which does sound slightly similar, then pit to it, even if you don't agree about the close sound of aw and uh, "pit" still rhymes with itself.
You don't pronounce muppet like pet at the end, so it isn't just "tih"
Slant rhyming is important in freestyling.
Like I said, why don't you take your arguement to a Rap/Hip Hop or even a poetry forum and see how far you get, go find one, post that, and see how thick you are.