I know next to nothing about Jim Sterling so I can't comment.
The problem with the last couple generations of Kirby console games is that they're painfully unambitious. I liked the first several Kirby games (Adventure, Dreamland 1 and 2, Super Star) and at some point, Nintendo decided that those games were too challenging so they went the other way and made these games brain-dead simple because I guess their target audience of five year olds (or whatever) can't handle anything other than an extremely linear game. As mentioned before, some of the handheld Kirby games that are more experimental tend to be better. The Kirby franchise has serious potential that Nintendo/HAL for whatever reason just refuses to utilize.
With Star Allies, the gimmick is three additional players or CPU and they don't add much to the game except for some moments where they fly on a star or form a circle or something. These tend to be gimmicks and you can only do them in a few locations throughout the whole game. I think the idea of having multiple characters around to solve puzzles or progress through the game would be a good idea but again, the utter lack of ambition means that they don't outside of a small handful of situations.
Going to play Ultra Street Fighter II next! Then I see that the last DLC pack of Fire Emblem Warriors is coming out on the 29th so I'll revisit that and finally finish the game. Looking forward to getting back into it.