I had time to play about with some of the ideas and to clarify the issue.
To summarize the issues first:
a) Any method adopted has to be able handle units of any size. (eg normal units are 3 or 4 stands but they may be 5 or 2 or even a single stand. 4x1 stand units should not have an edge on 1x4 stand unit.
b) I don't really want to be tracking hits on a dozen or more units
c) I don't want to lose the feel of the rules.
d) I want to be able to rationalize any drastic departures from history.
The first idea tested:
A. Disorder. Here a unit that suffered hits > its morale became disordered. If disordered again it retreated and lost a stand. This worked ok but did not feel like Hearts of Tin or Morschauser or MacDuff
B. Break Point. The 2nd option was to go back to the break point idea with no stands lost until the break point was reached. I had some issues with this, especially for 1 stand units but essentially it worked. This very similar to what I played for the last games but without the flucutations. Once the big red dot goes down, the unit is doomed.
C. Hit or Miss The next ideas were several variations of the existing mechanism. The winning one so far was as follows:
When a unit is shot at, divide hits by target morale (2 for regulars), drop fractions. the result is the number of stands "lost". "Lost" stands may be removed (not historical but very traditional) or may be just marked (closer). Agree on this before a game. Remainders are not carried over. When a unit rallies, a successful rally roll will bring back 1/2 of the lost stands, rounding down as long as at least 1 stand is active on table. If all stands are lost then the unit retreats off table/routs etc as appropriate.
Needs more work and some proper testing but it might avoid excess makers without changing everything.