When you lookup on the G/L accounts on a Sales or Purchase Line you see the entire Chart of Accounts. Generally only a few of these are actually needed in data entry.

As a minimum filter we should only see unblocked Direct Posting accounts. Ideally we should have a new field called "Show in Documents" and the option on these field could be "Sales & Purchase, Sales Only, Purchase Only, None".
Also have a hard coded (or have a G/L option to) filter on accounts that are unblocked, Direct Posting = yes & of type Posting

This will simplify usability entry and lead to fewer errors.