I don’t know about simple, but I had the same problem and came up with this oneliner for creating NTuples:
x,y,z = collect(zip(transform.(a,b)...))
If you absolutely need Vectors then add another collect:
x,y,z = collect.(collect(zip(transform.(a,b)...)))
But I’m still a newbie, so I’m sure there’s a better way. I’m curious to see what the pros come up with.