from 3k climb till 5k, mostly abuse imbalance hero last time, nowadays i only play pos 4 or 5, why? Simple, any tom dick and harry knows how to do last hit in 3k plus rank, it is easy to learn to be frank as any dota player, hit creeps and buy recommended item, however these carry will suffer and not come back if they are not babysitted, as mentioned, they are not 7k mmr carry player.

To be frank i rather have average skill carry then average skill pos 4 and 5, good pos4 and 5 can gank and create so much space for carry to free farm and win late game, shitty pos 4 and 5 basically will let your carry underfarm.

And of course, learn to speak nicely to your team and command when to push and back.