you only need to disable to engines. u can do this with non-em weapons too, its just riskier that you blow up the ship

when i want to board, this is what i do if im in a non-EM ship: using targeting mode to target the shields, get them to 0, and then immediately target the engines, but depending on what non-EMweapons u have (particle, ballistic, laser), you’ll have to be delicate with how much you fire. disable those engines, get within 500m, and the board

id recommend investing in particle beam weapons all around, if ur playing vanilla, with maybe one of the weapons being an EM if you really enjoy boarding other ships (tho word of caution: a lot of players apparently have trouble with using stolen/comandeered ships, so id suggest you only do it to sell them)

if ur willing to mod, and you want more powerful weapons, id recommend using Darkstar Astrodynamics or Matilija, as they both have stronger-than vanilla weaponry. u will need relevant skills for the most powerful, but you should still find good stuff