Have you seen that new meter pan, that is listed for 2 service cables to enter and they don't use a double lug? They use the single lug that looks like a figure 8, and they are listed for the 2 conductors under the one screw. Well, if you have, I have seen where there is two 4/0 wires under 1 lug, or two 2/0 wires. Now here is the question. How about two different services or two different size wires? say a 4/0 and a #2 AL wire? Instead of using a double meter pan, (200 A for house and 100 A for water heater) they just use that single meter enclosure with the two services? Am I making sense here?