Why not train on COCO and fine-tune on Objects365?

[Henistein]

As stated here RT-DETR-{R18,R50,R101} were trained on Objects365 and fine-tuned on COCO dataset. Why not the opposite?

I am curious because since you already had the pretrained models on COCO why not just fine-tune on Objects365. Is there a reason for that?

Thank you in advance!