How many hutches do I need

So I was planning on having two hutches for breeding does and one Buck hutch and then a rabbit tractor of sorts for all of the kits that we would keep to butcher. I've been hearing from some people that do to these stray dog situation having a rabbit tractor would be a very bad idea as it would not be a secure as a hutch with an fenced yard. Right now I only have two hutches one with a doe and a buck and the other with a dough and two kits. Should I plan on building two more hutches or one hutch and a rabbit tractor.

We use rabbit tractors for our summer feed out.  We made them 4 x 8 x 2 high wood framed.  We use 1 x 2 wire on the sides.  We also run 34 hutches for kitting and breeding stock.  We have lost more rabbits to dogs in the hutches.  The dogs go underneath them and pound the bottom out.  Dogs are our number one enemy at the farm.  They run cattle through fences and kill anything smaller than them for fun.  We have lost 73 rabbits torn out of pens and countless broken necks from their pens being pounded on.  I contacted the dog warden and she told me if dogs are harming livestock that I may get rid of them.  So far only 4 dogs have died of lead poison, but we haven't had an attack since last fall.  We put up a camera that runs all year now.  The warden told me that all she needs is a picture and she will go to the owner and ask if it is their dog.  If it is their dog they get a fine.  The last set of dogs were from a half mile away.  

You can use electronet to keep dogs away from hutches and tractors.  Not cheap, but probably cheaper than building fort knox level tractors and hutches.