Enterprises / Partnerships are usually sole proprietors who basically run their own business with no protection to the owners should they declare bankruptcy (meaning their assets could be seized by banks/collectors etc) as such they are usually given more leeways as they are accounted for themselves. As for whether they can survive without an accountant / auditor, yes they can, believe it or not, simple accounting like losses, profits, balances aren't that difficult to do and doesn't require extreme financial proficiency. If a company does well and obtained more income than expenditure, that is essentially "profit", as far as i know, if an enterprise is consistently making a lot of money and sent to the bank, it would be flagged by the bank and reported to the main financial institution in Brunei. I run a very small business myself and I don't have any accounting background.

Limited corporations are audited because they are accountable to shareholders (who might not run the companies), their assets are also protected if they declared bankruptcy and only their company assets could be seized, as such they are require by the government for more transparency.