Which day should I do shoulders?

I have been working out for two years now, and I have found a routine that works for me. Due to me schedule a 2 day weekly routine is what I can consistently stick to. As such I have one day where I do arms/chest + squats, and one day where I do back/core + RDLs.

The one thing I am struggling with is which day I should be doing DB shoulder presses. It makes sense to do them on my arms/chest day as it seems to fit into that routine thematically, but after BB benchpress, DB incline bench press, bicep curls, hammer curls, and skull crushers my arms are pretty much gone. I can do shoulder presses, but I need to drop the weight.

If I do them on my back/core day I can load more weight doing them. So which would be better? Do them on the same day as the rest of my arm exercises with a lower weight, or do them on my back/core day with more weight?

If it matters I train mostly to stay fit and strong, and am not too fussed about optics