Yes it’s all about controlling possession in the opponents half, not losing the ball in bad areas and pressing/suffocating teams in the opponents half. Pique-Mascherano is another example with little pace. In a Pep/ETH like system fast CBs aren’t needed. You do need an aggressive CB though which is what Martinez is.
You cannot just omit that they are both natural pressers of the ball, nor can we consider ourselves an oppressive offensive force, where, in all honesty, a lot of conventional, unwritten rules are non-applicable because the opposition are so crushed, fatigued and dispirited, any semblance of functional football goes out of the window for them.
Barcelona of that time, Ajax under ten Hag and any established Pep team, are playing by different rules and can get away with far more 'unconventional' things because of that.
Having your two CB's playing high, both of them being natural hunters of a ball, both being slow in their own ways... that is only going to work if nearly all football is played in the opposition half and all they're doing is recycling passes to the rest if the team. If ten Hag ever establishes such oppressive football with us, do you believe it will be with our current personnel, or that, at the moment, concessions need to be made?