I just saw something, it may not have anything to do, but I'll explain it:
I was watching Smash Run enemies confirmed so far in the SSB Miiverse fan page, and saw quite a pattern relating "Sagas number of enemies = to more or less said sagas reps".
For example, Pikmin has 2 enemies so far, Earthbound got one leaked (a living car), Pokemon has 5 so far, Zelda and Mario have tons (I know they are two of the most important sagas to Nintendo, so it's normal they have tons of enemies to pick, but it also could be slightly influenced by Mario's 2 newcomers and Dr Mario returning, and Zelda potential newcomer), Ice Climbers, Mii and Rhythm Heaven have one (whether they end up having reps or not, except for Mii), DK has 3 so far, two of then are Kritters and a rumoured "big muscled Kritter" boss (K.Rool confirmed?), Kirby has a lot too.
Aaaand, so far we got 4 Metroid enemies, plus a rumoured Kraid boss, I personally think that's quite a lot for a "not so loved" saga (Ridley confirmed).
Take this with a grain of salt tho, as according to my own theory, Kid Icarus should have 4-5 reps xDDDDDDDDDDDDDDDDDD