In live it do require garrison but as the same time it is passive. In the preview it is an active time ability which cost munition and replace the passive, which make garrison requirement a serious restriction, or if it not require garrison as you said then the issue is event bigger.
It does not require garrison:
"Vickers HMG Team
The passive bonus of the Vickers is being changed into a timed ability. This should allow the Vickers's veterancy 1 ability be more useful in the majority of situation.
'Take Aim' replaces veterancy 1 garrison bonus. Improves range by 7, accuracy by +15%, penetration by +6. Cycle a reload before activating.
Can be used in garrisons. 15 munitions."
I know it an issue, have pointed out but fallen into deaf ears.