The MacAlister thing is not bad, as for the defence you already have a very good defence, I just hope they don't get injured, because that's the last straw, but as they have enough money they can do that, besides Liverpool need money, then Madrid as they have good money can do their business in a very clever way, Xabi asks and Florentino buys, possibly they will put together a better team, a dream team, if so let Barcelona hold on to it.
Even though they have a very good defense now, it doesn't necessarily mean it will work well. When players get injured or suspended, it will affect the defense. This happened when they lost to PSG because several players were injured and couldn't play. MacAlister is a good player and I'm sure he could be a solution. There's no harm in Real Madrid considering buying him. I see Real Madrid not only having weaknesses in defense, but also in midfield, as there are no players capable of replacing Modric or Kroos.