I think his point is that most factions have some kind of Recon that mitigates any LOS limits that their TDs might have, ergo a Vet 2 self-spotting Jackson isn't a big deal.
ditto
OP is theorycrafting about a potentially OP vet bonus, well there are already a bunch of OP stuff sight wise like I listed and the vet 2 Jackson will have absolutely nothing on them
Well if you remove inv what do you give it as currently no one use them panther being only 50 more fuel
On the topic of jagdpanzers and the free predator ability:
JP's vet much faster and shell out more DPS, they're not just cheaper. Vet5+camo allows you to basically snipe Fireflies/Jacksons before they can even react. Getting a panther to vet5 is a much harder job.
swap the camo for mobility and I think it would still see the same use.