Well, obviously not that drastic. My point is, that Iniesta plays better further up the pitch and now plays deeper. A player like Gundogan fits just fine where Iniesta is currently playing.
But, imo, while Rakitic is also sometimes good in creating random actions, he is not our "classic playmaker" over 90 Minutes.
He will make some good deadly passes and assists from time to time, but he is not a guy who will try to find/create holes constantly for 90 Minutes.
While Iniesta is still THAT guy. (Even though Iniesta has a poor number of assists in this Season. But he is still trying and he is the "key" brain in our midfield)
Let's say that our midfield had 3 positions for the last couple of years:
Dmc: Busi
Mc: Xavi
Mc-Amc: Iniesta
-- while Xavi and Iniesta more or less play on the same position (left and right in midfield), Iniesta is always slightly more attacking oriented and he is closer to our attackers and to the opponent's Goal
In that sense, our Mcs on Xavi's position are:
-- Xavi, Rakitic, Sergi Roberto
-- Pogba, Gundogan, Verratti are somewhat similar to that position
Iniesta's position is slightly different, and imo, that is a position for:
-- Iniesta, Rafinha, Kovacic (those type of players)
About Kovacic/Pogba/Gundogan, imo, they are not exactly "shooting" for the same position in our formation.
I would personally love to buy Kovacic+Gundogan for 50 Millions.
Then we would have:
Iniesta's position:
-- Iniesta, Kovacic and Rafinha
-- when Iniesta will retire/decline, we can have Kovacic and Rafinha (if Rafinha will develop well)
Xavi's position:
-- Rakitic, Gundogan
Players need some rest, there will be injuries, red cards, a lot of matches in a Season.
I personally wouldn't like a midfield combinations:
-- Busi+Gundogan-Rakitic
-- or Busi+Pogba-Rakitic
-- imo, that is the same as Xavi-Rakitic midfield
-- we "lack" something, some attacking power (which Iniesta provides) in that combination
So, when people say that we need a midfielder, it is not exactly the same to search for Iniesta's type of a midfielder and for Xavi's type of a midfielder.
** Even in Rijkaard's days (and Lucho is more or less copying Rijkaard's system), our midfield had Dmc-Mc-Mc/Amc combination.
Deco was always slightly more attackingly oriented than Xavi.
-- Xavi was Xavi, the guy who connects ALL THE TEAM
-- and Deco was more like a 2nd playmaker behing Ronaldinho. Plus, he scored a lot of Goals from his semi-Amc position
(When Rijkaard bought Deco, he said that he bought him to create another playmaker, because Ronaldinho can't do everything alone. So, Deco was indeed more like a creator/playmaker, while Xavi/Van Bommel were just regular "midfielders" with different duties)
And also, Iniesta was always Iniesta compared to Xavi.
(So, we never had 2 Mcs who are exactly with the same attacking duties)