all of them need special tools, and its a lot more than the lower unit and 4-strokes.
every manufacturer has special tools to make working on their equipment easier for them to manufacture
special screw drivers for carbs, special wrenches for everything from the prop to the flywheel special locking tools to hold the flywheel, special gauges for setting gears, fixtures to align parts, etc.
can you do most of the work without them, yes, however having the right tool makes things a whole lot easier and a hundred times faster