Lambda actually can zone tao. It just happens to be more difficult than any other character. Learn tao's trajectories, and learn which tools cover said trajectories. Low j.D covers a lot of tao's approach, and with minimal recovery if it whiffs because of landing. 2D and 6D, and even 5D have their uses. Regarding 236C, tao actually has to respect that at certain ranges, as a counterhit means half her health. Also, tao's ability to keep in on lambda, while good, isn't as good as say, bang. A lot of tao's strings lose to IB+Jump, and her options off of 6B aren't consistently scary, also, if you see a 6B, why block when you can superjump. Tao's 6C is nice at catching lambda's backdash, solution: stop backdashing, lambda's backdash has a lot of recovery at the end of it.
There's a few other things, but I don't feel it's as bad as bang. (no, I did not contribute to this 100% correct matchup chart)