Not sure why it's an arbitrary stat, that's 1 win in the last 12 away KO games.
Who shall we compare it to? Ancelotti and Enrique?
Enrique in his time at Barca:
City 1-2
PSG 1-5
Bayern 3-2
Arsenal 0-2
Atleti 2-0
PSG 4-0
That's 3 wins and 3 losses.
Ancelotti:
Schalke 1-3
Dortmund 2-0
Bayern 0-4
Schalke 4-3
Atleti 0-0
Juve 2-1
Arsenal 1-5
3 wins 1 draw and 3 losses
Those two have won more away KO games in their last 6/7 than Pep has in his last 12. It's not an arbitrary stat IMO, it shows his tactical naivety away from home in the CL.
Let's do the comparison over a wider sample of games, shall we? All numbers below are statistics for away games in European knockout competition (CL, EL), excluding finals. I added Simeone's 3 losses in the Copa Libertadores because I was bored, but feel free to leave it out. First 6 managers have more than 20 knockouts under their belt.
Wins Draws Defeats Sum Reference
Guardiola 4 7 9 20 2009/10 inter
Ancelotti 6 8 6 20 2004/05 PSV
Mourinho 6 7 7 20 2006/07 Liverpool
Ferguson 8 4 8 20 2002/03 Madrid
Wenger 4 5 11 20 2003/04 Chelsea
Benitez 7 4 9 20 2006/07 Chelsea
Over his last 20 games, Guardiola has lost 2 more games than Mourinho, 3 more games than Ancelotti, and 1 more game than Ferguson. Not enough to distinguish him as tactically naive compared to those 3. Ignoring draws, no manager has a winning record in away games, and for good reason. They're tough contests. That's why even scoring an away goal grants you an advantage. Treating away draws as an advantage, the math comes out to
Guardiola 11 9 20 2009/10 inter
Ancelotti 14 6 20 2004/05 PSV
Mourinho 13 7 20 2006/07 Liverpool
Ferguson 12 8 20 2002/03 Madrid
Wenger 9 11 20 2003/04 Chelsea
Benitez 11 9 20 2006/07 Chelsea
Ancelotti comes out in front, but his 20 game stretch goes all the way back to the 2004/05 defeat at PSV. Fergie retired in 2013, and his stretch goes back to the Madrid game, a span of 10 years. Mourinho is ahead of Guardiola by 2 games, which is a fair assessment.
Below are the records of managers who have not hit 20 games yet. Of the bunch, Simeone's record is the most impressive, with 8 wins and 10 wins + draws out of 14 contests away from home. Conte has only 4 wins. Klopp has only one win, but his 6 win+draw combo was enough to see him through to 2 European finals. Moyes...
Conte 4 2 6 2012/13 Celtic
Klopp 1 5 4 10 2012/13 Donetsk
Simeone 8 2 4 14 2011/12 Lazio + 3 losses Copa Lib.
Pochettino 1 3 4 2014/15 Fiorentina
Moyes 0 0 2 2 I don't recall.
Overall, the data doesn't support the notion that Guardiola is significantly more tactically naive than his counterparts. The converse would suggest that he should have more CL titles to his name. That accusation can be levied at Mourinho, Ferguson, Ancelotti...