That is correct about the torque convertor mounting.
But the convertor also features a center pilot hub and bushing.
When you are separating the convertor from the flywheel, make absolutely certain the convertor is not "stuck" to the flywheel with rust. Because there is no relative motion between the flywheel and the convertor hub, it is not uncommon for a rust bond to form there.
Always try to sort of "spin" the convertor around a couple of revolutions by hand after you remove the last bolt that holds the convertor to the flywheel. Spinning it around like that helps to pulverize any rust that may be there.