Yes it is better to wait until Cup draw to improve your team, but if you want to buy Scouts, I think it is on Day 3 for the first update on the list of them.
Day 1,3,4 & 9 are the first lot of scout list refreshes.
I don't claim to be a Top Eleven expert but, if anyone would like advice, please don't hesitate to contact me through 'private messaging', I try to reply as soon as possible.