How to adjust system planning to not split order's Packages while planning?

I have an Packaged Item with weight 40 TON

And having 2 Equipment Groups

1st Equipment Group is "X" with effective weight 40 TON to carry

2nd Equipment Group is "Y" with effective weight 20 TON to carry

The case here is while Ordering 2 Packaged Items from this Pack

So total Order is 80 TON, in my perspective I can split this order to 2 shipments, each shipment will carries 40TON (1 Pack), but can't split a 1 pack on 2 shipments.

When I start planning on that order I have a plan suggestion for option with 2 shipments, each shipment will use Equipment group X as every shipment will carry 1 Pack (40 TON)