competition finishes

All the recent heated debate on competition finishes,
and how to change the rules to prevent beat ups, has
focussed on a minimum height finish, which also has
its problems.
Why not approach the problem from a different direction,
and have a rule that states a maximum speed within
a radius of the airfield, for example 70 knots within
2 miles or 5km?
This will not prevent competitors from converting their
margin to speed, but due to the distance that remains
to be covered, will ensure that it takes place at a
reasonable height.
Note I use the 70 knot/2 mile figure as an example
only. The numbers can obviously be changed as appropriate.