Graphics relative Animation length for differend actions




beginner and first time poster here,

i have a question that i cant seem to find an answer for, and im sorry if i miss something obvious..

i am working on my first game maker project, based on the famous platformer tutorial by shawn, but i allready adapted it to use spritesheets for multiple body parts.

my question arises from using spriter for the animations, it seems to be very tedious work to export and create spritesheets (non automated so far), so i wanted to make sure im going about it the right way...

so here is the question, i have learned that 8 keyframe animations are used for a walkin cycle, but how long should other animations be in relation to that ? like shorter animations for ducking or attacking, or longer ones like climbing up a wall,

does it make any sense to have these at fractions or multiples of the 8 frame cycle? 2 frames for ultra short stuff, 4 for short, 16 for long ?

i cant seem to exactly wrap my head around how all of this works in relation to timing ingame, or if i should just make them all the same length and just work with image_speed (or other tools) in game maker itself

if someone could elaborate on the basic concept, or give some insight on how you lay all this out i would greatly appreciate it,

thanks in advance guys