It's true, we don't see
CreatedById and we can't set the field history tracking on these. To be fair it'd probably be of little value as it could be wiped out anytime admin decides to click "recalculate" on a sharing rule.
The table definition (to which you've linked) says it supports
update. Well, yes and no.
Good luck with it ;)
AccountShare accshare = [select Id, AccountAccessLevel, AccountId, CaseAccessLevel, ContactAccessLevel,
LastModifiedById, LastModifiedDate, OpportunityAccessLevel, RowCause, UserOrGroupId
where AccountAccessLevel !='All' LIMIT 1];
accshare.AccountAccessLevel = 'All';
update accshare ;
Update failed (...) First error: FIELD_INTEGRITY_EXCEPTION, field integrity exception:
RowCause (cannot update sharing row with this cause): [RowCause]
My RealForceExplorer says that not a single field has "Updateable" flag set. I haven't tried all possibilities but common sense dictates "it's not auditable "more" because there's no need to". It is whatever it is, LastModifiedById is sufficient.
If you feel like experimenting more - hopefully "User X has hit [recalculate sharing] on all Account sharing rules" will show up in Setup Audit Trail? That way you could use info from SAT and manual sharing entries to determine the full picture... But combine this with "User X has changed the team membership in Group Y and it just so happens that this group is used in sharing", "user X changed Role of user Y"... Good luck with that :/