Here is a draft GR text which builds on Anthony's work and implements
some of the aspects discussed in this thread. See below for
comments/rationales and the attachment for a wdiff.
+ 3. At each review round expiries are processed sequentially, most
+ senior member first.
+ 4. No expiry can reduce the size of the Technical Committee to
+ 3 members or fewer. (It might thus happen that up to 4 members of
+ the Technical Committee remain in charge with more than 54 months
+ of seniority on January 1st. In that case, up to 2 of them will
+ expire at the next review round, provided that the committee has
+ been further staffed.)
Wording simplifications and fixes for my en_IT idiosyncrasies are
particularly welcome.