Here’s the thing. When we meet Frank he’s already spent a year dealing with Trapper’s hedonism and Blake’s apathy… so he’s on edge. He’s a good-to-great surgeon in ideal conditions, but conditions aren’t ideal at the 4077th. He’s feeling the stress.
He only manages a bit more then 5 months under the combined weight of Hawkeye and Trapper. They eventually break him and he goes home on a medical after losing 40 pounds and breaking out in hives all over his body.