36h @ 3 or 4 cross pattern was pretty much standard spoke count for most OEM wheels from the 70's to the first half of the 80's. Then from the mid 80s to the early 90's 32h at 3 cross started being more common on higher model sport and race bikes. I still remember how nervous I was when I built up my first 32h, 3 cross wheels, I thought I was going too radical with the lesser spoke count and might end up with wheels that blew apart on the road, which of course, never happened. 28h then started to be more common in the 90's when stronger designed rims and hubs became more available before the wheel suppliers started going all out with what was track only spoke count and patterns which at present makes 18 and less spokes and radial front wheel lacing not unusual anymore on bikes you can buy off the rack today.
For C&V, wheels I think as long you ar not a "Clydsdale" and is at or under 160 pounds, you can safely use 28h, three cross wheels with strong designed deeper sectioned rims like the aero shaped rims of the late 80's. I have a 28h aero section rimmed (Wolber Profil 20 with DT aerolite oval spokes and beefy Stronglight Delta hubs) wheels that feels much stiffer and stronger than my conventional section 32h, Mavic GL330 rimmed, 3 cross wheels. As long as you have the right combination of rims, spoke and spoke patter and not a heavyweight, I dont think you need to be too nervous about 28h rimmed wheels.
JMOs,

Chombi