I agree with @whuber's comment that moving parcel geometry to try to match area values is a bad idea. Since GIS features and layers are only representative of "the real world" it is often difficult to make the digital geometry match the on-the-ground features.
To me, your best bet is to stick with the geometries that are provided in the DWG (which were likely created using coordinate geometry input, or COGO, from "raw" legal descriptions) and simply attach the Excel values to the GIS features as an additional field. If you want to help users differentiate between on-the-ground values and digital values, consider creating something like "GIS_Acres" and "Legal_Acres" fields.
Definition: Coordinate Geometry (COGO)-
A method of defining geometric features through the input of bearing and distance measurements. Coordinate Geometry (COGO) functions are typically used by land surveyors to enter traverses around spatial features such as parcels, to calculate precise locations and boundaries sing distances and bearings from reference points, and to define curves using a point location, radius, arc-length, and so on.