If you can go running after a heavy hard weight session, & recover then you aint Training very hard in either weight Training or running.
So...no cardio after doing weights.
But...doing cardio before weights means you can't hit the weights hard.
If you run hard the day before you lift you can't lift as hard.
If you train legs hard with weights the day before you lift your legs will be tired and you can't run hard.
A quandary.