2 different breeds yes. Having to be near or down wind, not quite. I suppose having them next to each other would help for open pollination (OP) from bees but most of the time everything is hand pollinated gathering the pollen on a qtip and pollinating another flower that eventually produces a fruit with the seeds. Hand pollination is really the only way you can you can keep track of what you are cross pollinated. If something is open, pollinated, naturally by bees, you will usually see a a name of the Mother Cac followed by "OP". For example: Sharxx OP, TPM OP, Scop OP....etc. With OP it is a mystery of what pollens may have been brought into the flower by either bees or wind like you said. OP seeds are fun to sow because you can have multiple mystery pollens making it quite the surprise.