The lower General's "stack" wil lose the benefit of the lower General's bonuses and only receive the benefit of the higher General's bonuses in the overall stack since they are no longer part of the lower General's stack but rather of the higher General now. However if any unit has V&Vs affecting their individual stats, only the individual unit now - whether it be a General or a subordinate unit - retains those V&Vs for itself only.

Tomcat