My guess is that Fontenots now number in the hundreds of thousands in Louisiana. I would guess millions, worldwide.If I can find where I read this, I'll let you know. I thought it was in The Fontenot Book but I could not find it this am.
My primary ancestors, Morein/Ledoux, (Adam Morein/Alcina LeDoux, my parents); Morein/Ortego, (Pierre Morein/Marie Adiede Ortego, my paternal grandparents); LeDoux/Fontenot, (Villeneuve LeDoux/Adelaide Fontenot, my maternal grandparents), I can tell you, the Fontenots outnumber the others by about 4-to 1 - no kidding! I observed this when I first started researching in Fr. Hebert's books and made photocopies of the Fontenot, LeDoux, Morein, and Ortego individuals I was researching.
I have just printed a Marriage Report to use as "galleys" if you will, to assist me in editing my very large database. I have listed 1265 Fontenot males (married males only, females have not been sorted, so I don't know how many I have); 385 LeDoux males; 170 Ortego males; and 122 Morin/Morein males.
I also descend from Savant/Guillory (Jean Pierre Savant & Marie Louise Guillory); I counted 575 Guillory married males; 106 Savant married males. I also descend from Morin/Vidrine (Pierre Felix Morin/Morein & Marie Louise Vidrine). My Vidrine research is incomplete, however, I counted 182 Vidrine married males.
I am sure you've heard the joke about the Fontenot who wanted to change his name from Fontenot to Vidrine. When asked why, he answered "not so many Vidrines". He may be right!
You raised a very interesting question. It will be interesting to see what others have to say.
Another way to get an estimate is to count the Fontenots in the Index of your Fontenot book and compare to a count of the other surnames. You could include females as well as males.
I learned this past week that Winston De Ville has a book on the Guillory family that is now at the printers. I sure want a copy of that book. I need to find out how to order.