Combos without using order tag

I have a dilemma,

I have set up a menu with Half/Half pizza item, and added order tags for all pizzas available and set the min and max selected tag options to 2.

The second request was to have combo deals, so followed a similar path and added order tags to select 2 pizza types available for the deal.

Problem is, where the option selected on the deal is a half/half, will not invoke the half/half modifier.

I looked up automation actions/rules, and not sure if there is a workaround to select sub products from the original menus.

Can you show some screenshots/better explain?

So your combo offer is an order tag?