Play test its going to give you an idea of the strengths and weaknesses of your list. dont immediately fall into the typical war seer answer of spamming a single unit because some one else says its good. See if your list is lacking anti tank. I dont know who or what you usually play against. Where as my opponents are rather mixed and vary greatly i find it best to take a more balanced list. you might not fight mech guard or mech wolves heck you may not even see lasplas razor spam.
And do you guys play with a lot of terrain? very little or a medium ammount. you can always solve alot of your problems by deployment thats another aspect that people forget when their brain storming their lists. If you have a plan for how you wish to deploy and a general strategy then your list can and probably will work for you.
Me personally i like my unit of oblits but im more opt to deploy other units to see if they can work for me. Ie units like AC/LC preds even havocs. It all comes down to taste and use of any given unit. some times it may hurt you but thats half the challenge of this game if every win was so easy that it there was no point in playing the game because your opponent has better units or more of a certian unit then you might as well give in. me im gonan slug it out and make you bleed to earn a victory over me then again my win vs losses arent perfect on here as some peoples are....