What are the order of and prerequisites for creation of PersonInOrg records?

We have the following situation (One Identity version 9.2.1):
- some businessroles cause an account (ldapaccount/adsaccount/unsaccountb) to be created
- some businessroles change a fieldvalue in such an account. This is done by a process; This process checks a few times if the account is present before setting the fieldvalue. If the account is not found after several tries the process gives up.

Now when a new Person is created and the businessroles for it are computed it looks to me like:
a. the personiorg records are created in an arbitrary order, and
b. if there exists some process on the Person, the personinorg record is not created
(assumption b. I derived from the fact that sometimes the account is only created after the process that tries to set the fieldvalue has given up finding the account, and ended).

My questions are:
1) is assumption b. indeed the case?
2) is there any way in which I can influence the order in which personinorg records are created (so that I can give the busnessroles foor accounts a higher priority than those for the filedvalues)?