I cannot say whether that is a factor. I can say that it isnt the only one, because there are a bunch of longer term reasons why some countries responded better. Germany maintained a much larger ICU capacity over many years, and had a decentralised and large diagnostics industry which made a large difference in their ability to test in relatively large numbers. Merkel didnt scupper these things during her time in power, but I expect she is also not the originator of them, original decisions about these things probably happened a long, long time ago.
Plus the differences in timing and overall approach from Germany were not radically different - they were a bit different, and the testing regime clearly had a notable effect, but its not like they were miles ahead of everyone else when it came to lockdown, it still took what happened in Italy (and then Spain) for lockdowns to suddenly be considered viable and essential in the EU.
Recently Whitty said that when he talked to his German counterparts, they werent too sure why they were quite as successful as they appear to have been so far. In some ways this sounds like a very silly thing to say, but in others there is probably some truth to it. Partly because erring on the side of caution means they do not want to judge themselves as a big success yet, early gains, even impressively large ones, could still be lost in theory. And the reasons for the successes so far may be a combination of the obvious things we all seize upon (testing, hospital capacity) but also some others that havent really been in the spotlight yet. We know that infection control in care homes and hospitals can be quite the difference makers, and could presume that Germany had some success on these fronts, but some of those successes could have been down somewhat to luck or some existing characteristics of their care home sector or societal behaviour.
I could also suggest that gains made by Germany were amplified by the timing. In theory locking down one week earlier in the epidemic wave would make a very notable difference to how big that wave got. But its not just a question of pure timing, the key is timing of lockdown relative to stage of epidemic at that moment. So if Germanys epidemic was at an earlier stage when they locked down, because for example their testing regime had slowed the growth there during some key weeks, then this ends up being somewhat equivalent to having locked down weeks earlier than some other countries, even if they were not actually weeks earlier based purely on the calendar.
www.keeptalkinggreece.com
www.politico.eu
