...and yes, the problem does lay in the fact that you dont want the receivers to ack, you just want them to be told what to do (as you cant have multi recievers all ack'ing back at once using the same pipe etc)
This was why I was trying to find a way of giving away the next tx/rx channel within the transmitted packet, and a possible frame count down until switch over. (It was never going to be as fast as FHSS), so at least this way the transmitter was always in charge of the sequence of channels.
My original idea (and the one I had published somewhere) was for the transmitter to do a cleanChannelScan at start up, to determine the best channel to transmit on. With my pseudo-hopping technique I was going to scan for the best 6 channels, and use those as the sequence of channels in the hop
The big question was 'what if my receivers lose track of what channel it should be going to next ?'