No, to be specific, it doesn't depend totally upon one's attitude till the post of DPO. Everyone gets a chance to serve in the field especially in the early years of his/her service. Right now, Pakistan has around 145 districts including ICT and major cities like Lahore, Karachi, Peshawar etc. PSP doesn't have a plenty of officers so everyone gets a chance to serve as a District Police Officer throughout his career at least once. Government would not put you on desk for ever. But as one gets to higher rank i.e DIG, then the real competition starts. Higher authorities definitely see your profile and reputation for the post of RPO (to command a full division). For IGP, the competition and the list goes thinner and very few officers compete for that post. And yes, your reputation and "Hello Hi" with senior authorities also plays a vital role for you in getting better posts. Actually, it happens in every group i.e PAS, FSP etc. Its Pakistan after all.