Both are reporting directly against tables, record selection formula as follow
{OINV.CardCode} = "CSG00113" and
{OINV.DocDate} = {?Posting Date Range} and
{OITM.ItmsGrpCod} <> 148
Both are using the same formula, but there is slight variation in the database
Report 1
Report 2
Despite the number of tables in Report 2, if I placed the same database or identical formula fields into the report, the result will be the same as of Report 1.