I just came from a job last week changing out all the lights above a counter. They were in a row, three all together in one series and on the other cabinet top four in a row. Not side by side but end to end.
The system was piggybacked with a 3 foot of wire joining two with one then three with two. One Switch controled all lights.
Not being an electrician, I just re set them the same way they were installed originally and they worked just fine.