Lets see..
Magneton: Weakened by (in red/blue/yellow) ground.
Rapidash: Weakened by water, ground, rock
Golem: Weakened by water, ground, ice, grass, fighting
Starmie: Weakened by grass, electric, bug, ghost
Vileplume: Weakened by fire, ice, bug, flying, ground, psychic
Snorlax: Weakened by fighting
Slowbro: Weakened by grass, electric, bug, ghost
Well, you have four weakened by ground for a start. Nowadays you'd be completely pummelled to death with a team like that.
My team would be (if we're strictly speaking red/blue/yellow):
Electrode: Weakened by ground.
Starmie: Weakened by grass, electric, bug, ghost
Snorlax: Weakened by fighting
Arcanine: Weakened by water, ground, rock
Butterfree: Weakened by fire, poison, flying, ice, electric, rock
Dragonite: Weakened by ice, dragon
Two weakened by ground, two by electric, two by rock, which isn't too bad. There are better teams sure, but still, would be good enough to kick your teams ass .