Slightly different approach. I use two PH 135's paralleled to the inputs of two (2) Block Power Controllers Total power is 270 watts about 15 amps at 18 volts. Each PH 135 has a 7.5 amp cut-out. On dead short de-rails they both open at the same time. The PH 135's input/power two (2) TPC 400, kind of a big off on switches, with the ability to run variable voltage if needed in conventional mode. The Outputs of both TPC 400 are wired as input to (2) BPC's, which allows for (8) switched track circuits via the Cab1 remote.
Cranked up to this power level (15 amps), then each of the (8)output of the (2) BPC's is fused at no more than 7.5 amps. There are (8) blocks or power districts from two transformers. May be a little less costly than a brick/TPC per loop.
The Lionel part to parallel the transformers to a TPC 400 is 6-14194.
Note the picture
(1.) PH 135's paralleled lower left.
(2.) Track Power Controllers,TPC 400's lower right. Note the parallel connection part, 6-14194, lower right of the right silver box, TPC 400.
(3.) Block Power Controllers, BPC's upper left below and to the right of the large accessory transformer. Each BPC can input from either TPC 400, and has (4) out puts. There are (8) track circuits.
(4.) The (8) track circuits are fused, (7.5amps), from the outputs of the BPC's before wiring is routed to the tracks. Fuse blocks are to the right of the large accessory transformer
This set-up seems to inhibit a lot of the arc and spark welding on de-rails from the higher amperage/power available from parallel-ing transformers.
Block Power controllers.
(8) Track circuit fuses (7.5 amp) upper center picture.
Single line wiring diagram.