The way I do it is this:

UAT: middle line (top of cap) goes to Pump, pick one side fitting doesn't matter which one (this is for filling and will need to have a removable plug), the other side fitting runs to a t which goes to the saddle tanks (the two equal size tanks). The lines going from the t to the two side tanks must be equal in length - moreover, each clunk in each side tank must be equal in length.

Next the overflow fittings on top of each side tank are t'ed to a t fitting which in turn go to the single clunk line on the middle or top tank (the single smaller one). This tank gets filled and the overflow from this tank goes outside the jet to the overflow fitting.

So as the pump runs, the middle tank will empy first being sucked by the two side tanks, then the side tanks empty, then the UAT.

You can test it without running the turbine by filling up the tanks with your fueler and watch the sequence of fill. When you fill, the UAT fills up first, then the side tanks fill up next then the middle tank fills up last, and the overflow goes outside the jet. When you suck the fuel out with the fueler, the middle tank empties first and the saddle tanks empty, then the UAT is the last to empty.

I'm not the best at describing things but this may help. I noticed the BVM shows one of the side tanks not having a clunk. I don't see how that would work with a three tank system.