i'll have to agree with bryan on gen 42 ff.
couldn't have said it better myself.
your example of gen 11.5,8 is also good for showing that banu 'built the
city and tower' suffix-tense that it is, can sometimes be used in
incomplete situations.
not unexpected for a two-value TAM system.
languages can tolerate some ambiguity and overlap, so that the lxx at gen
11.5 use an aorist. it focused on the action that had already been
completed by that time, at least some of the city and perhaps most or all
of the tower (tower isn't mentioned in 11.8).
of course hebrew 1 k 15.17 should be read as the aorist it is, 'he built'
and lxx said ---?
aorist wikodomhsen !