Carbons are nowhere near as consistant as alluminum shafts , not even close . Genraly a slightly stiffer spine will not adversly affect a release shooter , shooting a compound bow . If you were shooting a recurve with fingers the stiffer spine would have a greater adverse effect on your accuracy .

Now if they had given you slightly weaker spined shafts , you would have had arrows flying everywhere , even worst than what you have now .