Shipping?
Check out the group in my sig if you Smash shipping ye
headcanon
Smash personnel aren't any specific instance, but rather incarnations, copies. Travel in the multiverse for the fighters is restricted by Hands Limited, the group which controls the rules and matches for the viewing pleasure of multiversal entities known as "Miis."
None of the fighters have made the logical leap: "if the Hands have so much power, why do they bother with this real estate to keep us and feed us? Why not just skip straight to the battles?"
It's because they also offer other entertainment, mostly lighthearted stuff since that's the sort of thing Miis are in to.
Now you may ask if the Miis are so powerful that they're multiversal why do they have
any interest? Nah, they're just like any other physical sentient being: limited and finite.
In their high advancement they've developed a love of 'novelty' and 'realness' as opposed to their great arsenal of technology. The Hands, also a multiversal group, are capitalizing on this, so of course they don't tell the Smashers anything.
They get paid in gold-pressed latinum
Romance does come up, so does drama. One of the romances that I can see happening naturally due to the
character of the characters is Marth x Zelda. EZ. They have a ton in common it's like come on.