No you are wrong.
Try hitting a vehicles with AT grenade from RO and see how fast it vets.
And since flamer in your opinion are "Kings" the king of vetting are CE with their lower XP value, their superior Mosins, merge and higher XP value targets.
Not really and for 225/90 units it probably UP.
Doctrinal bolstered Ro.E with 210/60 cost are better and come with snare.
Assault engineers wipe the floor with pioneers and are available from CP 0.
This is where your bias is obvious
Snare is not a perk when your mainline infantry completely lacks AT grenades. One or two snare squads max vs 4 snare squads for any other faction.
Flamers DO vet faster than UKF RE in an average match, this is plain to see in any 1vs1 cast. PIATS even if unlocked don't come until late midgame at earliest when flamer pios are already vet2
You also ignore the fact Pios and CE are fielded earlier than UKF RE. Funny how you list all the great benefits allies have but you conveniently forget to mention any faults or things they lack