Dealing with alters to big tables coming through different change sets

We recently adopted liquibase and it has greatly simplified the task of getting DB in sync with code.

However we might have a problem in using liquibase in production. 
The issue in automating the schema application for production is the alters to big tables coming through distinct change sets at different times. 
Team 1 checks in “alter table bigtable column1” , Team 2 at later point adds “alter table bigtable column2”. 

It would take lets say (30 mins ) to run the alters independently in production as opposed to 15 mins if they were part of a single alter stmt wrapped under a single changeset. 
We cannot merge them into single change set as it would break liquibase changeset checksum validation.

I would very much appreciate any insights on how folks in general are dealing with this scenario.

Do folks use precondition to get around this issue?