I decided to do some testing for some hard numbers:
math will save you some effort next time.
reload on the support gun is 6.5-7.1 seconds. multiply that by .87 and youll only save .85-.92 seconds per shot. the fact is, the old modifier of .4 was making weapon teams fire more than twice as fast. that was clearly not balanced for things like AT guns and mortars, but doesnt make a huge difference on small arms (which i believe is what relic intended these officers to be used for).
the officer is still useful. it gives small arms a 10% accuracy bonus, which means all your infantry will do 10% more dps, but doesnt help mortars/support gun much.