Although I've moved this into the Labour Relations forum, I suspect the answers really depend on a variety of issues.

From a labour relations point of view:
• Can I argue that the company should make equal contribution to all members regardless of the employee’s choice 1 or 2 or 3?
The theory behind TCTC is the employee is given the latitude to structure their pay package to be the most effective for them and what they want their money to go to without affecting the total cost to company. If you standardise the portion reflected as "company contribution" to one-size-fits-all, all you're doing is reducing the employees' options. So I gently suggest this might not be worth pursuing.

• Can one request the company to reflect their contribution as employee’s voluntary contribution?
Given that we're talking a TCTC environment here, the question probably is not so much whether you can request this, but more whether it is advisable. This is where the investment/tax gurus need to give some input, I think.