The funny thing is that the current Barça team isn't even playing pragmatic football either. There is a clear difference between playing cowardly football and pragmatic defensive approach. There has been a lot of good teams that played attractive, entertaining pragmatic football in the past but Shitverde's team isn't clearly one of them.
Nah, he is a pragmatic manager imo, based on the loose meaning of the term. He is just only a 'good' one, not a great one. Also, many pragmatic managers have had success playing a more defensive style. The issue is their defensive setups were more drilled, with better work ethic. Just better defenses for the type of low block we're using often. Defenses who can resist long periods of pressure much better than our does. Or, dare I add, can do.
This Barcelona side doesn't give you that vibe. Yes, we survive often, and win quite some games 1-0, which is okay I guess, but at the end of the day, there is less defensive control than we got from great defensive sides like Juve, AM, Inter, or Chelsea back in the day. We kind of ride our luck in the sense that the opponent creates more chances than it is required for this defense-based approach to work, even if we're talking about half chances. Half chances is a tricky subject, because at a certain level, most goals are scored from half chances. You rarely see goals score in 1 vs 1 cases at this level.
Also, the nature of a half-chance is changing depending on the teams you face. A loose ball 16m away from goal into the path of Rashford is not the same as a loose ball at the edge of the box on Cristiano Ronaldo's right foot. Mistakes you make against big teams are punished more swiftly as the level of the teams you face increases. So, maybe United couldn't shoot on target from their chances. But I remember Juve scoring us 3 goals from 4-5 chances who weren't even that clear back in 2017.
For Valverde's style to work in CL, we need either better counter attacking, or better defending. Or, ideally, both. Great pragmatic-defensive managers have managed to have at least one of those two operating at very high levels with worse squads than ours. That is the difference really.