Brake Line routing

Working on a 93 Toyota Paseo, and noted something odd about how the brake lines are routed. Out of the master cylinder are two lines that go across the firewall. One goes into a 3 way block, the other into a 5 way block.

The 3 way block goes to the RF, and the 5 way block goes to the LF and both rears. And then there is a line that joins the two blocks together as well.

Maybe a picture will help:

but WHY? that seems awfully convoluted because you still lose all brake pressure should one of those lines burst (ask how I know).

Couldn't something simpler have been done instead?

My ASSsumption is it has something to do with using the same lines for ABS/no ABS cars. I would be a betting man that that 5 place distribution valve has two very distinct circuits, and one is a pass-through for the LF.

The 5 way block is the proportioning valve, it uses the LF circuit to supply pressure to make the PV do its thing. If there is a switch on that block, it's for the circuit failure warning. Loss of a line on either the front or the rear will move a shuttle valve inside the block which will turn on the BRAKE warning light. It probably was done that way either as 93gsx says to allow for an ABS system or to ease assembly of the RF hard line. Save time on the assembly line = save money on the assembly line.