If money is your limiting resource, then that's not an efficient choice. Go with the smaller inverters.
If roof space is your limiting resource, and money is not an issue, then going for more inverters (lower DC/AC) is a good choice.
If roof space is not your limiting resource, and you want more energy produced than you'll get from a 35 kW DC / 26.6 kW AC system, it's not clear whether you are better off adding more panels, or bumping up the inverter size. Probably more panels, but a more detailed analysis is required.
Thanks for your help Wayne (and others). My roof is maxed out with panels, that is my limiting factor. I've decided not to push for 4 7.6 and 1 3.6 but I think in the long run I'll be happier if I do go with four 7.6 instead of three 7.6 and one 3.8....even though I recognize it won't make a huge difference. If Tesla doesn't want to do that then I'll go with their recommendation. Thanks for helping!