homebrew – Should Healing Skill Be A Trade Or Knowledge?

Heal (in my "Medical" game) is a bit of a weird skill in the system that I write and thought I wanted to get advice from others. I wonder if you think Healing should be a skill based on craft or knowledge.

In my system, all of the crafting skills require a character to actually practice crafting in order to advance the skill. That is, if they want to advance their forge, they will need metal to work, an oven, a hammer, an anvil, etc., and literally do something, if not for themselves, then for an employer (another blacksmith) in exchange for money or a rebate, etc.
However, knowledge only requires a person with access to more knowledge, through a tutor / teacher or a book / manuscript on the subject on which they wish to know more.

With that in mind, where do you think Heal as a skill would fit best? … and would transportation around body parts to dissect later be hilarious or reasonable? LOL