I use a table saw quite often and I know that hardwood will bog down a three horse power motor
easily and that is just one blade. Multiple blades are going to require
a lot of power. For instance, look at this thing
http://www.directindustry.com/prod/maquinas-pinheiro/automatic-multi-blade-rip-saw-21872-50641.html

That is a multi-blade rip saw and it has a 100 hp motor. There is also
the problem of feeding. A ten inch blade with a one inch arbor and
washers is only going to give you a feed capacity of 3 inches or so.
Then how do you keep the blades from quickly grabbing the wood and
binding up? If you have the blades cutting so they pull the wood they
are just going to grab on and stall the motor. If you have the blades
so they push the wood they are going to spit whatever you put in there
right back at you.

I have also had carbide teeth come right off saw blades from feeding too
fast and hitting a knot or nail. It would be a real pain to have to
take apart the whole blade stack and replace a blade every time a tooth
comes off.