I've never specifically measured the pump, but i've measured other circuits in the car. The headlamps for instance are wired with 1.5mm cable draw less than 5A and manage to drop nearly a volt between the battery and the bulb.
The standard wiring for the pump is also 1.5mm in size and protected by a 15A fuse.
The datasheet for an 044 indicates its maximum draw is 15.5A, however this is likely to be just before the lockout pressure, rather than 3 bar.
Some graphs:
http://forums.rennlist.com/upload/bosch_044_flow_chart.gif
http://www.jayracing.com/images/products/Jay Racing Pro Series 044 vs Bosch 044.jpg
Both of these suggest at 3 bar the pump will draw around 10A, and once under 1.5 bar of boost the draw will increase by an amp or so.
The OEM pump will probably draw slightly less, lets say 7A.
So your suggesting that in wellys case, drawing 17-18A thru a 15A fuse and wiring designed to run 7A's worth of standard pump isnt going to cause any voltage drop?
And in your case, 2x044 and a intank probably drawing over 25A is again working perfectly thru the standard 15A fuse and 1.5mm wiring and your still getting a nice healthy 14v at the pump...?