Cena has his "5 moves of doom", and so does Orton, HHH, and so on and so on.

Cena has the STF,Throwback,a variety of suplexes,5 Knuckle Shuffle,Leg Drop type manuever,and the almighty,Attitude Adjustment

Orton has the DDT,clothesline,the Boot,and RKO

Yeah,Orton has a more limited moveset and I dont think he cares or even trys different moves while Cena actually trys to improve.Since people like Orton more,they dont notice