He's taken down people better than deadpool b4
None with a healing factor as good as Deadpool's. Atleast not in a random encounter.
Even though it's a random encounter they meet each other before so they do have an idea of what the other is capable of..
While Deadpool holds almost every advantage, but Punisher has proven in the past to be more than capable of taking him down.
Deadpool's greatest asset is his im-predictability and his ability to keep his opponents distracted at all times.
However, to someone like Frank, those tactics just don't work well. People often underestimate him, but he has fought, and won, against the best of them through superior skill, and overall better tactics and ridiculous pain tolerance.
Deadpool is my favorite character, but in the past Punisher has proven to be his kryptonite.
Thanks for reading,