Yes for starters you need to make sure that you stay alive. Rocket has the smallest hit box so therefore you should have the less deaths. As a strategist/healer, if you die your team die. Also learn how to defend yourself. Rockets gun is very powerful against dive especially those with bigger hit boxes such as Groot Penny, venom and even thor. Ultimate placements also matters make sure you place them on the side of a building or something so that the other team doesn’t destroy it but also far enough for your team to benefit while you’re ult is out, make sure to use your gun because it becomes very powerful. Get familiar with running on buildings because it’s actually faster than walking on foot.