You can kill a Sarissa, while a Dread will require a lot of luck.
If you get killed by Outcasts in Tau 23, its not really the ships fault. I'd blame it on the numbers you will have to fight there in most cases. (There is just no chance that you can win against more then one Battleship, or one Battleship with support in a Zephyr)
An yes, its going to be dealt with. The 4.86 Zephyr will be different, so you wont have to worry too much about being outgunned.