Because having Slim and Lazarus on the same team would be a downright amazing buff to Laz. You can actually be stealthy now, instead of fluttering around with your jetpack after one revive, waiting for your cloak to recharge. And no more trying to be as stealthy as possible, just for the Monster to see your health bar and go focus you down.
Right now smell and health bars are probably Laz’s biggest counter in the middle of combat. The monsters bound to find you with these two things, but Slim can take them away. I’m already fantasizing of the epic clutch moments. If there was a support, assault, or trapper with the ability to take away the monsters ability to smell and see health bars, like slim, do you think it would make Laz viable, when he’s teamed up with one of them?