With the Treacherous Ground talent, you can prevent Grohk from using his Ghost Walk. With moderate levels of anti-healing, you can potentially kill him even through the healing of his totems.
Don't fight Maeve if she doesn't have low health! Position yourself to the high ground on the back so that she'll need to use her movement abilities to get to you. If she does, group up with your tank or teammates and "spam" VBE to get assistance
When andro comes for you don’t panic try to land 1st bullet then he will take nether step to make more damage at this time use stealth and he will go crazy now land another sniper shot if you miss quickly switch pistol and spam left click.