Matching Cartridge + Headshell + Tonearm combination

My general question is, if a tonearm works optimum with15g weight for cartridge+headshell, any combination of weights would be OK? For example, 5g+10g, 6g+9g, 7g+8g, ..., 10g+5g of cartridges and headshells would all work well?

I am going to have Denon DA307. The catalog says the cartridge range is 5g-10g with the PCL5 headshell (6g). My specific question is, would DA307 work well with 9g headshell with 2g-7g cartridges? (Well, I know almost all cartridges weigh more than 5g)
Thanks.