No ... if you want World of Tanks please close the door behind you.
But also YES ... when a vehicle is being operated by multiple people it should take multiple people to counter it.
You can't simply say "HAVs cost loads so they should take more people to kill" or "I've spent X mil sp so I should be indestructible" ... isk and sp costs are irrelavant when looking at the balancing between 2 equal teams ... if one person calls in a HAV that requires 2 people to counter, you're left with 14 people getting stomped by 15 people and a HAV while 2 people try to survive long enough to co-ordinate an attack ... in this case simply remove AV weapons from the game as the only counter to a HAV is another HAV ... and as I said World of Tanks is that way --->
So as I've said balancing sp costs and isk values is a simple matter of CCP's choice without the player driven market, but balancing the effectiveness of vehicles can be done by giving skills for infantry to train so that when they are gunning in someone elses vehicle they provide bonuses to all sorts of things, from weapon tracking or damage to movement speed or acceleration or defensibility with bonuses to active repairers or resistance modules or even base hp values.
This way you can justify taking more players from the other team to counter it, if it's taking more players to operate it ... AND you're giving operators incentive not to try to solo dominate a battle if they are weak on their own.
For this to work you'd obviously NEED the ability to remove a lower skilled gunner in favour of a higher skilled one.
It could also operate like Fleet bonuses in Eve where the FC decides which person provides bonuses, so the operator selects the higher skilled gunner as the booster, but then you could add in a 50% increase (for example) to the bonus from having the third gunner seat filled.
This could be set up in different ways, but the best way I can figure would be the vehicle itself has the bonus from a gunners skill, so say the Caldari HAV has a shield boost bonus, so you'd need a gunner with the "Gunner shield subsystems" skill at level 5 with a third gunner to get the maximum bonus ... and gallente HAV could have an Armor Resist bonus from the "Gunner Armor subsystems" or Amarr having tracking bonuses from the "Gunner Electronics systems" ... the possibilities are endless (and the skill names need work I know !)
This way your sp and isk investments are secured by using teamwork, which then has the knock on effect that you want, requiring teamwork to counter it, while still leaving a balanced infantry fight going on around you.
[TLDR] = Too Lazy, Don't ReplyDigest / Disect / Discuss / but most important of all AGREE