I know a seed sprouts whichever way you plant it but wouldn't planting it the best way around give it a head start?
Maybe, but the kind of head start we're talking about doesn't really significantly affect the size, number, or earliness of pumpkins it'll grow, which is generally the part we care about.
It's true that favorable seed orientation can benefit emergence. In other words, if you planted two seeds "rightside up" and "upside down", I think you'd have a decent chance of seeing the RSU one break the surface slightly sooner. (Now I kinda want to do an experiment).
And in the very early seedling stage, a head start of even a single day above ground does result in a visible size advantage, so it'll seem like that one is way more robust. This is where it's easy to make the leap and figure that that one always will be more robust, and at the same magnitude compared to the other one, but it doesn't work like that. The advantage quickly gets lost as the plants mature. By the time the plants are flowering/fruiting, you wouldn't be able to tell which is which.
(Think of the way you could easily spot the size and developmental difference between a newborn and a 1-year-old kid, but that difference would be indiscernible if you looked at them at ages 40 and 41.)
The main reason I'm sure it doesn't make a noteworthy impact on health or yield is that I've looked at a bunch of production recommendation sheets for commercial growers, and none of them have mentioned seed orientation. People whose livelihood depends on producing as large and high quality a crop as possible would take care to plant their seeds just so if it was worth it.