I'm surprised at how poorly some remember Mario.
I have a very hard time seeing Ancic doing what Soderling/Berdych can do on clay and other slow surfaces.
Ancic's baseline game wasn't as good as Soderling/Berdych and with the trend that everything goes slower he hadn't been favored.
He actually reached QF at RG in his last semi-full year on tour (2006) only losing to Federer. IMO, he could actually do better than those two on slow surfaces, he had one thing those two sorely lack: the ability to grind out matches. The best example of this (but not the only one) is on one of his last comebacks when he beat Murray in the third set tiebreak in Indian Wells in one of the ugliest matches you'll ever watch. It's the kind of match Soderling and Berdych lose 90% of the time (especially against very good players) - when their weapons aren't working, they struggle greatly to just stay the course and grind out the win.
He didn't have the firepower these 3 have.Soderling,Berdych,Tsonga are much more attacking players with stronger groundstrokes and stronger serve overall.Only Ancic advantage would be his net game.So no,no way he would've been better than any of these 3.
Eh I'm pretty sure everyone would agree that his BH is at least better than Tsonga's (and probably Soderling's too). I agree with your broader point that he probably has the least power off the ground among those 4 - although if we're being fair here, Soderling and Berdych increased in power when they peaked which Mario never did. He more than compensated for it by moving better than them and being able to follow his big shots into the net (a weakness that has held back Soderling and Berdych in big matches against the top players).
And no way are their serves better than Ancic's. They might have a bit more power, but Ancic's serve is more reliable and varied. Only Tsonga is his equal (maybe slightly better) in that department, someone like Berdych would kill to have such a reliably strong serve as Ancic, would probably have spared some embarrassing defeats. Look at the highlights of that match with Ferrer I put in the OP: Ferrer was already one of the best returners on tour and yet he barely got a look at Mario's serve (although, of course, his serve wouldn't be so deadly on other surfaces).
He had a fun game, but did lack power. He did do alot better early on than the other 3 mentioned, but actually seemed to get more inconsistent as time passed. He should have been able to win a masters the Ferrer-way, and reach at least the semi's at Wimby 1 or 2 times, but alas..
Could this have had anything to do with his history of injuries and mono since 2006? And he did reach a semi at Wimbledon, could have reached more if he hadn't bumped into prime Federer in 2006 and 2008 in the QFs.