The sucker (runner) top growth is doing better farther away because it's getting into spots that have better conditions. (And will not be sapping the shoots that came up closer - or the original plantings - unless these runners are, in fact rootstock sprouts. In which case the scions are going to be sort of cut off or discarded eventually, as the stocks replace them with their own tops).

Suckerous species of roses can spread like running kinds of bamboos. I once had Rosa rugosa 'Alba' go under the paved private road here and come up in the yard across the street. (The surprise shoots were definitely growth from a runner and not seedlings, that would have started out tiny and slender-stemmed).

I see what you are saying maybe light, soil, etc. If I could see *any* reason that the new shoots had better conditions it would be easier to understand. I grow all my roses in tended beds and try to do all the proper preparation and add compost, but perhaps there was something in each case that I was overlooking. I did remove a goatsbeard that was several feet away, so that might give the rose more of a chance. I do admit that last year I did not cut out the suckers because they were growing so much better I considered removing the parent and just leaving the suckers. But....when I tried to "cut the cord" the babies didn't have enough roots to last on their own. I have also had shoots of my William Baffin roses come out in the lawn. I don't mind them in the lawn, and sometimes it's good to have a "spare".