I agree with you. Xavi proved that you don't need star players to build a strong squad. Leverkusen's squad does not have any star players. However, they are still unbeaten in the Europa League and Bundesliga. The team is ahead of Bayern Munich in the Bundesliga.
Xabi's match strategy is excellent. Xabi has managed to create a friendly relationship between Leverkusen's players. The understanding between the players is very good. This is why Leverkusen's performance has been so strong this season. In every match we see the dominance of Leverkusen players.
Perhaps in this case you mean Xabi. But on the other hand saying that all Leverkusen players are without star players is also a mistake in my opinion because after all Looking from the current condition several player such as Wirtz, Arthur, Xhaka, Frimpong or Palacios are a series of name that cant be doubted in terms of names. although not as big as some other great player like Cristiano and Messi or young player like Haaland or Mbappe but some of the players owned by Leverkusen i think have above average skill quality when compared to club in the other Bundesliga.
But on the other hand this does seem normal if the comparison is Bayern or Dortmund but honestly if the comparison is with other clubs then I think for the Leverkusen squad it still looks quite luxurious at this time so with its current performance then it is very good for them.