It's a good idea to give them a sling to use. The magic they possess will be weak at first, and they are very quick to die in battle. Each attribute will be assigned between a three and an 18 in score, though you rarely see less than seven on anything. Your two key fighters should have 18s on their strength, dexterity and constitution. Nothing else really matters for them, so cut them as low as nine on each of their other attributes.
Dexterity improves the chance of ducking an arrow.
Put your healers and modest fighters in the middle, and send your wizard to the end of the line. In case you were wondering, there is NO such spell. However, if Mandar survives to higher levels, he will have access to several spells that might as well be called such. The more creatures you can see, the more you are seen by. It is better to pick off one at a time, rather than be swarmed by a horde.