Agree, all he had to do was go to the bank and withdraw money to pay for the cover. Why didn't he?
Or why did he waste money on Holt instead?
Because we needed cover for Benteke in case he got injured. If we didn't have Holt we would have Bowery as cover and that is why Lambert cannot win, people would moan about that too.
And we would have had Helenius. Vlaar has been injured regularly since he joined . He was by far and away the more likely to get injured so the need for cover was greater with him.