The ability to explicitly create an order of execution for automations rather than relying on the last modified date would be beneficial to Smartsheet Designers. My suggestion is to add a dependency dropdown box as part of the trigger box. The dependency dropdown box would self-populate with the names of automations already created (much like column names do). The default selection would be something like "No Dependency" or just be blank.
Relying on the modified date is a recipe for breaking a business process. E.g., I use automation to route document approvals to multiple reviewers. If I update one of the various workflows that drive this business process, then the e-mail created during the approval block does not have the correct suspense because the Record Date automation ran after the next action in the approval automation. (Note: This situation could be remedied if the "Record Date" action was not a terminal action).