>>13177133Octopus AND tank. Remember its japanese name is "Okutank" and "Octillery" reflects this. Not only this, but Remoraid's japanese name is "Teppouo", and "Teppou" means "gun". So it's a "teppou" (gun) evolving into a "tank". That's the whole concept behind them.
>>13177141Why? Scyther needs no preevo. It can evolve into Scizor, a pretty decent Pokemon by itself.
On the other hand, Pinsir needs to be balanced with Heracross given both come from the same concept: beetles. Heracross is powerful and gains access to several moves. Pinsir is powerful aswell but can't deal that decently. Either both need an evo or a pre-evo so both can get similar moves.