Multiple plugins for same message on same entity

What is recommended way to handle multiple plugins for same message on one entity? 

For example, we have a custom entity called ABC, a Post Update plugin is already developed and deployed by an other company but they wont supply us with code so we have no other option to write new plugin code from scratch for several entities to achieve results/customise functionality. 

In above case we have written a Post Update plugin on entity ABC and it works fine but is their down side of it?

Or can we just change/update Execution order and it wont harm anything?

Thanks for any suggestions.