It makes sense why they would choose these six for the initial team, due to several similarities to past villains or backstories: Reptil has the power of dinosaur, which can be very unpredictable if left untouched. Striker is a glory hog with electrokinesis, and if Max Dillion is anything to go by, most electrokinetics are gonna be trouble. Hazmat has the hallmarks of the typical Hulk bad guy; a person in a containment suit with highly radioactive powers. Veil is a bullying victim with the later discovery that she can turn into poisonous gas. And Finesse is supposedly the daughter of Taskmaster, one of the greatest mercenaries of all time. Mettle seems to be the only one who can be seen as safe of this batch besides his anger issues, due to his upbringing by peaceful parents in his backstory.
Fridge Logic: In-universe, the team points out that while Jeremy Briggs has a point about the destructiveness of superhuman fights and how many superhumans waste their potential on vigilantism, he doesnt actually adress the cause of most Crisis Crossovers, such as Fear Itself which he specifically brings up - ungodly powerful alien, magical or technologial threats (or sometimes all three), none of which his depower tech works against, as it only depowers mutants and mutates. All his plan would really do is ensure that Earths metahuman numbers are depleted and make it much, much harder to defeat the next big threat, which is going to come wether Spiderman is around or not.