Why does the Haynes manual go to great lengths to explain you don't have to remove them to split the cases.
I want to get my cses vapour blasted so they are gonna come out anyway, the manual mkes me feelI'm gonna enter a world of pain: is it such a big deal?
The Haynes manual is right, but I have always had an easier time getting the crankshaft out of the timing case after the pinion is removed...in my experience it has always been easier to take the crankshaft out of the bearing that to get the crank, bearing and pinion out together, even after heating the case. Don't worry about causing yourself any 'pain', the pinion is keyed in place anyhow, so it's really no big deal.
I don't know if you are talking about timing pinions or the crank pinion, this thread seems to be talking about both at different points.
Historically Haynes manuals are at best sketchy, at worst they are misleading, get a decent copy of a factory manual, they are free all over the net and far more detailed.
Crank Pinion ? separating the crank bearing from the outer race was frowned upon by some as it was more likely to get damaged. You have to remember that most of these books were written for workshop "repair" not "rebuild"
Timing pinion ? much easier to leave in place if you just need to split the cases to get to the sludge trap, but then people without pullers try to push the cams through (which works great till the key cuts a nice new key way through the bush.