Yarbles,
There are many ways to capture a field and the one you describe would work ok in most scenarios.
If you want total control over the battle I would suggest an NOE attack run on the key elements of base defence.
Take out the ack, VH and ord. Having tanks on the field for cap will only work if these 3 things are taken care of first. Usually a co-ordinated strike would be best rather than letting the GV's drive up and do all the work themselves it would take way longer and the chances of the defence to get up much more likely.
Towns can be taken care of in two ways. A good bomber in lancs can take 3 passes and leave around 5 buildings left. Or a good osty driver can wipe the town and ack in around 5 minutes if they are good. I prefer the m3 method best as usually they are less noticeable than a goon.
After saying all of this timing and the element of surprise are the two biggest factors of base capture in my opinion. Many a time my squad have managed to pull off a capture against superior odds due to skill and outsmarting the opposition.
Nothing beats watching the ack pop and seeing the enemy get torn to shreds by it
Regards
Bruv
~S~