If you attract stronger baddies, you get more points for killing them and level up faster. Sometimes I will hold back on a level-up when a character is 1-2 points away from a new spell level (level 2=15, level 3=30, 4=45, 5=60, 6=75, 7=90) and I will work that spell realm until they qualify for better spellpicks. Normally I promote as soon as possible.I have run 5 Wiz 7 transfer teams with good weapons and armor. And I have run 3 startup teams with Monastery-issue equipment. All had trouble on the road, and all were around level 7-8. Level is not the problem. Weapons are not the problem. The road is easier if you are patient and know your enemies tactics and weaknesses and know your own strengths and weaknesses.
When the bad guys are blinded, they run away. Do you have flash powder or (better) blinding flash spell? Even level 1 can thin them down to a managable level. Paralyze? Freeze Flesh? Noxious fumes? Insanity? You don't need to kill them outright. You need to stop them from killing you outright.
Are you standing in the middle of the road?
Do you have missile shield, armorplate?
Of course you have used that circle-with-colored-dots-on-the-right to arrange your best players in front and weakest in back.
Do you have x-ray? The most useful spell for traveling Arnika Road or anywhere else. It lets you see whats coming and RUN AWAY. Remember, he who turns and runs away lives to turn and run away another day. It also lets you watch the movement of the monster groups, allowing YOU to choose when to attack a single group. Do not let THEM choose the time or terrain.