I'm considering sweeper upgrade and vet2 as well, which isn't hard to achieve at all with them.
Upgrading sweepers on all other engies means you won't even see vet2 as you'll have 0 combat potential to get it.
Problem is sweeper upgrade no longer grants repair speed (for unknown reasons it got ninja'ed)
Also:
With Veterancy 2
Sappers: 3
Pios: 2.6
Combat Engineers: 2.6
Rear Echelon: 3
Sturm Pioneers: 2.6
Vehicle Crews: 2.5
Anvil sappers gets superior 5 repair speed, while they take 6 popcap.
Pios and CE vet quickly with flamers
Vehicle crew get vet2 no time
Sturms hit vet2 quickly only with flamers, without it - it take ages.
Come on Katitof you are smarter than that - Please dont tell me You dont see it.