I'd wager that smaller clumps of structure, staggered, forming a line from one area to another would also serve as a great highway. Semi-natural fish highways are creek channels in a reservoir - picture along depression with steepish sides, littered with cover.
Instead of buying the pvc and corrugated drainage tubing you could probably save some money buying PEX in bulk and using it instead of pvc. The large tubing cut in half could also be made of plastic drums.
I added some green to your plan to represent areas I'd add cover - mostly near bedding areas, provide highways between beeding areas, cover in pinch points (natural highways) and transition areas from shallow to deep.
I added a single 20' cedar in my pond last year that bridges the transition from 3' to 14' of water. It is heavily used year round by both predators and prey alike. I have a 50' oak that fell into the pond years ago, the trunk lays shallow from bank to 7', always has a bass hiding under it. The top transitions from 9' to 3' and holds yoy fish and predators year round. Be sure to vary your cover types as stated above.
