3 Re-rolls is likely all you will ever need, so starting off with some reliability is a good idea. Jezzail is a good ball handler, and does not get sent off. 2x Mech Vermin gives your team some toughness, and Doom Flayer is the most reliable and effective of the weapons at your disposal. This is a conservative approach to the team, but likely the most effective. You could also swap a Clan Rat for a Apothecary if you like.