can you make 2 screenshot for us...

hero with the kazar's bow... clik your castle, click statistics, click military, click general info, scroll down to training speed and do a screenshot...

in my case, it look like :

second screenshot, equip the bow and clik your castle, click statistics, click military, click general info, scroll down to training speed and do a screenshot...

how it work ?

in my case, without bow, i am already at 545.5% ... if i add the kazar bow, it become 545.5% + 24.8% = 570.3%

if like you, i was having 54 sec without bow, with bow it will be 51.651 sec

once you have done the 2 screenshot, write down the value training speed from first screenshot ( ST1 ) and second screenshot ( ST2 )

formula is : new time = old time * ( ST1 / ST2 )

For calculate anything in this game, trust on value that you see when you click your castle... when you check only your hero, you don't see value from research, city skin, shaman, etc...