I find that moves like "Iron hand" gives him an advantage, it can surprise your opponent through most attacks, just like Paul. Heihachi's eishomon has good range, comes out quick, and attack low, so it's very good to mix it with his 3 hit combos like lp, HP, HP, or lp, lp, HP. Jin is a bit slower, and his combos can be memorized by your opponent if you play him often, but he has combos that ends with attack low, which is why I say they can reflexively block given time. Heihachi's 10 hit combo 1 (number 65) doesn't have to be completed, just input the buttons up until he 4 hits. So it goes, forward, forward, HP, lp, HP, HP...most people will find that heihachi comes at them fast without them being able to do anything but block, then you can just throw or do another attack.