People often say "Just buy a striker/midfielder/CH" etc, but it really must be a taxing and nerve wracking time for the vast majority of clubs. Those with wads of cash can usually get their way, but even the mega rich clubs lose out.
We express interest in player A who would be perfect for the squad, but he can't/won't commit until he sees what else is on offer.
We then look for an alternative, but we can't do much about the fee or personal terms because we're still hoping player A will sign.
Then we have our players being targeted by other clubs. The price isn't right but the player wants to go, or maybe it's the reverse. Do we have a replacement in the squad? If not, is one available.
It sounds like a nightmare to me and I'm only scratching the surface. No wonder it's so difficult to get right.