Use your ultimate to keep people away, the optimal time to use it is overtime on center.
in case of pushing the payload, you can put it in front of the cart.
If Barik is running One Man's Scrap on a high level try to use CC (To prevent Barik destroying them himself) and avoid the turrets to prevent this form of healing.
When u play barik make different loadouts for turrets, shield, demage and try to counter the enemys build. Try to make uncounterable loadouts, for example do not make a loadout just focusing on turrets cos thats easy to counter with bulldozer card.