>>54309788it wouldn't surprise me that the multiples evolution was a mechanic that got dropped.
catch 3 magnemite for magneton
catch 3 diglett for dugtrio
catch 2 koffing for weezing
catch 1 slowpoke + 1 shellder for slowbro
besides, they make sense, magneton plays on magnetic attraction, dugtrio plays on the whack-a-mole motif