the weight will be useless as the domainhash will define wich service to use without taking the weight into account.
If you want a 2-3 ratio, I would suggest configure services with same info but different names like
proxyrc_1.1
proxyrc_1.2
proxyrc_2.1
proxyrc_2.2
proxyrc_2.3
You also get a 2-3 ratio and the domainhash can now see that that are 6 servers [even if only 2 real servers].
Regards,
Gilles.