Yes you can supply it with an array in the format ["Sudeep",Ghatak"]
The email task completes as soon as you make a selection. There is no separate approve button.
Just thinking of it again, why can't you have a simple email like below, with a link to a SharePoint/PowerApps form where the approver selects the second approver and saves the form.

The flow gets triggered (as it checks for item modified), checks if the approver 2 column has a value, it goes forward else terminates.