I'm not entirely clear on what you mean. You're saying that in your game your monster DEFENSEs *and* your player DEFENSEs are too high? Or that their SOAK is? It's hard to comment without seeing the exact situation. What sort of SOAK scores are your players peddling?
When I was talking about monsters trading dice, I was speaking specifically about their damage output. Using the Amazon from the bestiary as an example against a Player with the same pool limit of 6d6, the Amazon uses its Shortsword to attack the player's Melee Defence (which is 21 since they have it maxed out) so the Amazon has a less than 50% chance of hitting the player (with 5d6) and only if they trade no dice for damage. Assuming the Amazon hits with the Shortsword, they deal between 4-14 damage but the player has Scalemail so they have SOAK 6 which reduces the damage to between 0-8. Furthermore, since they are a player they have HEALTH based on END+WILL+LUCK so they have at least 9d6 HEALTH, meaning they could have 10 HEALTH (since that is the minimum) or they could have 54 HEALTH but for the sake of this example lets say they have the average static value of 32. In the best case scenario the Amazon has to hit the player over 4 times in order to kill it.
Note that this purely an example but hopeful it helps highlight the situation that I am getting at better. All of my players have between 5-10 SOAK from Armour so any creature that only uses basic attacks (1d6) has no chance of seriously hurting them unless their static damage bonus is 6 (i.e. 1d6+6) which is fairly unlikely.
On the other hand, what I was talking about regarding defences is pretty much dealt with by lowering the creature's defences below the pool limit. Using the example above, it sort of works at the pool limit too but the issue for the players is that without positional advantage they would have a much less than 50% chance of hitting the creature if they traded dice. Of course, they should be using positional advantage so assuming they trade dice from that then they should have a 50% chance of hitting then. That said, when this is pointed out to my players, most will still not trade dice since they feel they are better just ensuring they hit and dealing the damage since the monsters probably have less HEALTH then them. This is entirely their personal opinions on that though so the next combat will be a good test to see if I can convince them otherwise.