Gonna bump this as I have a similar question. What about using both pickups with a filter on each, teed together into a single line. For redundancy. Is there any issue with that???
Not to get too deep into fluid dynamics but this would add resistance before the tee (think of it as doubling the weight of the fluid being lifted by the pump and reducing velocity by half) and create one more point of failure. If one of your two lines gets damaged either inside or outside the tank, you'll have an air leak and pull air into the system. Both lines would effectively be rendered useless.
Reliability comes down to using good fuel line (Nitrile, NBR/SBR blend or Viton), tight connections (good zip ties or Oetiker clamps), a chemical-resistant filter that flows at least 10-15 GPH minimum (avoid sintered bronze elements), and clean fuel so you aren't risking a filter clog. One fuel line per fuel pump is more than enough.
