Hi there.
At the schema compare, tables and triggers were once separated from each other, so if there's was change in the table, but also a change in the trigger, you could generate isolated scripts accordingly to yours necessity at the moment.
However, this has been changed since the version 7.4 or so. I must say that it's terrible now. If the scenario I explained above occurs, I have to be careful when generating the sync script because now both elements (table and trigger) are considered as one. If I have a local change on both but only want to deploy the trigger, I must select the table at the compare, generate the sync script and be sure to remove the "alter tables" that are also generated, otherwise things can get pretty wrong.
This type of change breaks a workflow that we have been applying at our company for more than 4 years. I believe that you should really consider to add an option to separate those elements again.
Table and trigger at schema compare
Re: Table and trigger at schema compare
In the next version 8.2, this will be resolved. Triggers will be considered as separate objects.