For the sector 3, why do you want to allocate 8 PDCH statically ? It might reduce your TCH capacity too much during the busy hour ?
The configuration of each timeslot is not very important, you can put the TCH or SDCCH anywhere you want.
For 4 TRX, it is recommended to have at least 2 SDCCH’s.
So 1 BCCH + 2 SDCCH + xx TCH
and thanks to parameters, you can decide to allocate up to 10 PDCH dynamically (MAX PDCH = 10) and 1 PDCH statically (MIN PDCH = 1)