It would be even better, if:
a) you could «compress» selected tracks into one, like placing all the drums part in just one row to organize your project. could be great, if you made a draft in the suggested sample-per-row mode and then switch to the default mode after such «compression»
b) if two samples use the same place in a row, would be amazing if Play could render them into one separate sample, optionally
c) They could be colored, so user could easily read the row
such a workflow would provide the best of two worlds, imo. however, I don’t expect it to be implemented even in the most basic form, putting all the wet fantasies aside. choosing and/or copying samples all the time may be painful indeed, slowing the creative process by a lot.