AD&D combat, as written, can seem weirdly complex, with "segments", "weapon speed" and other strange bits. When I dug into it, I found that it was more about presentation than actual system! Not terribly complex at all!
Here's the cheat sheet from my 2019 podcast on AD&D combat - maybe it will help you?
https://drive.google.com/file/d/1buc4Iubou-bH7V1Ud-h_4SkHm9wfm64a/view?pli=1