Reduce S&H if delivery is getting consolidated

Hi Team,

We have a new requirement to reduce the S&H if deliveries are consolidated. Lets say

1) Same customer have two orders O1 and O2. O1 has $5 S&H and O2 has $5 S&H.

2) We have few custom process which authorizes the order.

3) If both orders gets authorizes successfully then we give it standard picking process. If both orders are eligible(same ship method and same ship to address) then they gets consolidated to single delivery. If not they will go in separate delivery.

4) We are not worried about separate delivery as we are charging correct S&H.

5) But if they consolidate we have to reduce the S&H on both order to match total of $5 or reducing on one order will also solve the issue.