Battlecast: Industrial, war-like
Mecha: Hot Wheels and Transformers combine
PROJECT: Metal Gear + leather + Deus Ex
Program: Circuitry, circuitboards, bare technology, bare hardware, robotic
i: Sleek, white and blue, smooth and clean.
Full metal: Technologically powered battle suit, like Master Chief.
I'd say the i-line is part of the program line(you can see lots of iblitzcranks in program lissandras splash art). I mean the creator line is also part of the battlecast line,so its not like every member of the skin line has to have the same name in it.
Also fullmetal is kinda like a mixed bag. Jayce looks like he has a powered armor,Pantheon looks like he simply wears armor and Rammus looks like a robot...
To add onto what you're saying...
Mecha: Has some Pacific Rim, Gundam and Neon Genasis vibes.
PROJECT: Future dystopian
Program/I: Faux utopian iRobot singularity vibe.
battlecast and full metal r meh. love the others.
