How To Set Rules For Promotion For Large Product Group

I have a vendor that has a range of T-Shirts which come in multiple colors and sizes.

He would like to run a promotion where a discount is applied when 2 t-shirts are purchased of a specific type.

He has normal length t-shirts and short cut T-shirts. If 2 of any normal t-shirts are purchased a discount is applied.

With all the variants this could be any of approx 200 products. How can I create a rule set for this?

I tried setting up 2 rules with all the products in the list with 1 of each using the any rule in each set.

This applied the discount when only 1 item was added to the cart.

I need 1 of the list + another 1 from the list = discount.

Thanks for any assistance, this has me stumped.