Currently some structures don't heal garrisoned units (<BuffHeal> is 0), others do (1), and temples (3) and wonders (5) heal at significantly higher rates. However, it seems a bit haphazard, e.g. civic centre and elephant stable have 1 but fortress and stable 0.
Additionally, there are two technologies, one for the barracks (+1) and one for the temple (×1.5 i.e. +1.5); they both cost 500 food, 250 metal and are available in the town phase. Having multiple technologies that basically do the same thing for different structures is rather inefficient. Besides, it begs the question why only these two have technologies, and not any other structures.
This patch makes the 0 rate the default and merges the technologies to a single one, researchable at the temple, but affecting garrisoned units in all structures, except for outposts and walls (i.e. those with visible turret points). The new situation is:
0: structures by default 1: structures with technology 3: temple by default 4: temple with technology 5: wonder by default 6: wonder with technology