I would prefer to spend our money on guaranteed first team starters ,even it means only signing 3 players for 100 m
Holgate ,Mina ,Keane and Gibson if rated should do as CBs
We need to improve the first 11 as a priority and put our present starters to the bench.
If we want Europe we need a stronger first 11 and not intentionally buy squad players
I think we are really at a quality not quantity stage. Look we may fall away, but if we can maintain the performance level we have shown over the last 7-10 games (or ensure any drop off in not major) we are showing top 5 form in the current league as things stand. It may even be good enough form to finish 3rd. Even if that drops off a touch, you'd imagine this squad is good enough to show top 6 form from the moment Ancelotti arrived until the end of the season.
That is without Iwobi (for the most part) Gomes, Gbamin, Sigurdsson, Richarlinson (partly) and players such as Mina, Digne not at 100%. You start adding those players back in, particularly the 2 lads in central midfield and the team has a very different feel to it.
If we have a spell of showing that form, I do not forecast us ripping up our squad to start again. It will be slower evolution with adding 1 or 2 as you say. I think the club need to decide what position they see Holgate playing and probably buy someone for the other. I suspect they will view him as a centre back, so another midfielder will be good, personally I'd like to see another centre back with him shunted forward.
It's probably not what people want to hear, but players such as Bernard, Iwobi, Gbamin etc are going to be given more time to start to make a first team place their own, and I think they will do ok when that opportunities comes.