Same problem, 2007 VP 2.4L 4. It has a slower cranking speed than my sisters 2013 Accord with the same engine. It turned over about 2 cylinders a second and starts on about the 4th to 6th cylinder when cold--- faster when warm but it is 30 to 40 outside.
I changed the battery using a small 12 volt printer nicad battery clipped in the + and - of the fuse box and ground to keep the voltage up. It cranked slightly faster with the new battery.
Charged the battery up with a remote charger to 14.5 volts and when it only took a tenth of an amp to keep it up to 14.5 volts it cranked faster but not as fast as my sisters car.
Changed the ground cable with a 12 gauge one that went directly to the block and also to the nearby fender. It cranked slightly faster but not as fast as my sisters car.
Cleaning the starter solenoid terminals (both from the battery and the second to the starter) requires the intake manifold to be removed and new gaskets may be the next step.
The original Bosch replacement starter draws about 20% less amperage than an American replacement which is cheaper. Maybe it has the lower amperage Bosch starter that might crank slower.
In most engines that crank for some time, it is the crank sensor that has to give 4 pulses before the compute recognizes the Cam sensor to start firing the plugs. In others it fires right after the cam sensor pulses. Have not read how this beast works.
A weak cam sensor might require many more crank revolutions before the computer can see a pulse of sufficient voltage to fire the beast up.
I have not yet purchased a manual for location of these sensors but Autozone, Advance etc might be able to point them out to you so you can ensure the terminals are not corroded if it is cranking fast but not firing up.
Always remove and replace the plugs on sensors 3 or more times so the wires can bite into each other. Any corrosion reduces the voltage --- some times enough to cause long hard starts.