Tiggs Boom splash radius+ hits more parts? Google not helping

I noticed mainly moze having bigger tiggs booms

And there being skinny tiggs normally with other ppl? Is this pure splash damage or something.

Does the tiggs work like a lob spawning?

Is thee size related to splash damage modifiers or aoe damage? What increases the damage of meteors besides weapon damage.

Points in Torgue Cross Promotion?

I only have one of these, so don’t have any context for comparison.