Hello Russell,
Happy New Year and welcome to the forum!
Totally agree with HRF above, Hornby points are insulfrog which makes life 100% simpler! I have been modelling 40 years now and still use insulfrog points, like you I don't understand electrics, but this hasn't detracted from my enjoyment of the hobby.
From your post the layout you are building is for your children, my advice therefore is to keep it simple so that trains will run and that will keep their interest. If you go off into the realms of sectioned track, and that means soldering contacts onto the rails, the likelihood is that thing will go wrong, trains will stop, and the children will find playstation more interesting (ahhhhhhh).
I describe myself as a well "below average modeller", and having the electrical, and mechanical, aptitude of a dead frog, the adage of "keep it simple stupid" works for me. No detriment to anybody else, indeed I am in awe of the excellent sectioned layouts that appear in the MR press, and on this forum, not to mention the excellent capabilities of DCC, but I honestly don't think I could master the complexities.
From your trackplan, the two feeds indicated will make the layout function fine, indeed a third controller on the very inside track could make 3 trains run at the same time, that's just what I would have wanted as a little lad! HRF's advice is good with the points switched either controller could feed a section of either loop, so be careful, but your plan is sound and will get 3 or possibly 4 more people interested in an excellent hobby, due entirely to the purchase of a train set at Christmas. Well done!
Happy modelling (and that is what it's all about!)
regards,
Clive