Gazza M people always say "we needed defenders" in comparison to "not signing defenders", but it should be in comparison to signing forwards instead. Nedding defenders in isolation isn't really an argument - nobody thinks we should spend less on defenders so that we can put the money in the bank.
Although when I say this, the counter-argument is often that it's not about prioritization, and that we have money available but forwards simply aren't available.
Although when I'm mad about not beating City, the argument is that they have so many more good players than us because of their money.
