number of locos.

It sounds like 4 locos for the current schedule is a ballancing act (I guess last season's three locos at start up was worse).
Kyle had 6 locos (thanks to J. Bush, Earl, Coker and company) for a few years.
For the current operating schedule:
1) are five servicable/operable locos reasonable?
2) can 5 handle charters or chould a sixth loco be available?
3) would a seventh or eighth loco (i.e. 483 and/or 492) help?
4) would the same seventh or eighth loco make the routine maintenence more difficult (i.e. too many for the shop crew to turn around without increasing shop crew size)?
On a slightly different line, Has the "Train to Cumbres and bus back trips" hurt the Osier round trip loadings or has it actually helped the bottom line?
Thanks
Doug