Well, I mean, I think having them is great, but when you have, like, a 1/300 chance of getting Shadow the Hedgehog from a Capsule, it begins to become problematic.
I see what you mean from one perspective. I do like the surprise though instead of seeing the same faces over and over. But from my count this our 29th Assist Trophy we have confirmed. Some may be rarer than others, but I'd say 40 or more is reasonable.
Chain Chomp (Mario Bros.)
Hammer Bro. (Mario Bros.)
Lakitu & Spinies (Mario Bros.)
Ashley (Wario)
Waluigi (Wario)
Skull Kid (The Legend of Zelda)
Midna (The Legend of Zelda)
Tingle (The Legend of Zelda)
Mother Brain (Metroid)
Dark Samus (Metroid)
Metroid (Metroid)
Knuckle Joe (Kirby)
Nightmare (Kirby)
Andross (Star Fox)
Lyn (Fire Emblem)
Magnus (Kid Icarus)
Isabelle (Animal Crossing)
Samurai Goroh (F-Zero)
Takamaru (Nazo no Murasame-jo)
Saki Amamiya (Sin & Punishment)
Starfy (The Legendary Starfy)
Nintendog (Nintendogs)
Dillon (The Rolling Western)
Shadow (Sonic the Hedgehog)
Elec Man (Mega Man)
Color TV-Game 15
Prince of Sable (For the Frog the Bell Tolls)
Devil (Devil World)
Dr. Wright (SimCity)