Unless the rules have changed recently, it makes no difference to the community schools where you put them in order of preference. So you should apply to them as many as possible (ie all 3). The faith schools have their own rules so read those carefully and follow them. I think that for some of those they do want to be first choice.
In Richmond the schools are so over-subscribed that there's not much choice, and you might try to train yourself to think about parental preference rather than parental choice. You get in based on distance to the school, almost regardless of what you put on the form. You can stay on as many waiting lists as you like though, and it's worth doing that. Places do get offered to waiting list children, but it is incredibly stressful being on a list, particularly if you have no place at all.
The council's education department are very helpful. I suggest you call them. They won't be able to predict what will happen this year, but they should be able to say whether your child would have got into the schools you'd like last year or the year before. Make sure you ask whether the place would have been offered initially, or whether it would have been a waiting list place. The school in question would also have a pretty good idea, if you are able to pop in and sweet talk the secretary.
The DSs school took a bulge class this year, so we could have had 60 in reception. But by the time the decision to accept a bulge class was made, and letters sent out it was June (!). Understandably many parents felt they could not hang on in limbo waiting for the council to get its act together, and went private. So we now have about 45 in two reception classes, which is great in terms of ratios, but has appalling funding implications for the school.