Archie's had good writers for their "Adventure Series" stuff for some time, though Sonic has been on and off in the past (and currently, it's totally on).
The outfit Leo is wearing is his Cyber Samurai armor; it was based on the toys, when for whatever reason it was said the comic had to promote them (something they didn't seem to do a whole lot of-- or at least, if they did it, it was usually ahead of the toys' releases, and far better). So, they apparently decided to implement the Cyber armor (Shredder and Bebop's were left out) in a setting which made sense, one which was already established and had proven rather popular.
Also, I think writing credits go to Mirage to some degree.
The armor was also featured in one of the last seasons of the cartoon, but in a completely different context, one in which it belonged to aliens, and putting on the helmets made these suits take on different shapes and grow to Megazord-size. I guess the toon wanted it to compete with Rangers or something.
Sadly, Mike's was the one wrecked there, too.
Nonetheless, I've wanted these toys for years upon years now. I should see if I can find them at an affordable price. Or pester Playmates to release them as part of the 25th Anniversary.