Ok wait... so what units do you actually want to use?
You don't want arty, you don't want assault, you don't want emp...
Game is designed in the way that every group of units has specific role, and every role has units that can fulfill it.
For breaking porc there is assault, deal with it. Use arty and emp to weaken it first.
But if the porc is really too strong and you can't break it just go around. You have no idea how many games I have seen where someone keeps wasting units attacking the strongest defended point, while there are 3 other ways to go around and kill undefended enemy base and eco instead.
Now if you fear counter attacks from the porc it means the enemy has both more porc and more mobile units than you, which means he probably also got better economy, so you must have failed at some point and deserve to lose... :P