Data management Sequence

Assuming you can confirm with your tests that overlapping is the issue here and you cannot reasonably change the setup of your sequences and rules (on which we in the forum have zero visibility), you might want to change your setup as follows.

Only trigger step 1 and in the business rule that runs last, kick off the other three steps from the rule itself. This way you should be able to ensure that step 1 is completed before you kick off any other step.

You can trigger DM sequences by using BRApi.Utilities.StartDataMgmtSequence, BRApi.Utilities.ExecuteDataMgmtSequence, or BRApi.Utilities.QueueDataMgmtSequence.

StartDataMgmtSequence

This starts a DM sequence, i.e. it runs the sequences (possibly) in parallel if you start several at once.

ExecuteDataMgmtSequence

This executes a DM sequence, i.e. it fully executes the first DM sequence, then the next one. etc. This always waits until the previously "executed" DM sequence has been fully completed.

QueueDataMgmtSequence

This behaves like StartDataMgmtSequence, except that this one creates queued tasks that are considered by all DM servers (i.e. you possibly spread the DM sequences across different servers, whereas StartDataMgmtSequence executes DM sequences only on the server the business rule is run that executes the DM sequences).

I hope this helps you getting the execution order right.