Actually, the objective of Soresu to redirect attacks using the most efficient moves possible perfectly counters the heavy, powerful strikes of Djem So. A Soresu user will outlast a Djem So user by a wide margin, and when the Djem So user starts making mistakes is when the Soresu user find an opening to exploit. Soresu uses the power of the style against itself to wear down the opponent into making a mistake. Soresu is the reason Obi-Wan won the fight with Vader in episode 3. It's similar to how a Jiu Jitsu user is pretty much always going to beat a wrestler. The wrestler may have power and weight on their side, but Jiu Jitsu is designed specifically to use that against them.

Makashi, however, is all about finesse and precision, the perfect counter to Soresu's efficiency because it doesn't tire out the user like Djem So does, and its strikes are all aimed at specific targets. It's why Dooku took Obi-Wan down so fast in Episode 2, and anakin was able to hold him off for so long. The finesse of Makashi has a difficult time countering the power and ferocity of Djem So. 

Trust me on this. I've spent a great deal of time studying the subject. Lol.