There isn’t anything like an “intended strategy”, but there are a lot of missable pieces that could potentially make it harder.
What I usually did in my test playthroughs is: Marge uses Willpower, then Strong Attack over and over; while Motrax alternates between Fire Breath and Ice Breath.
If you don’t have a weapon, or if you don’t even pick up Marge, or if you don’t grab the Tail Ring that gives Motrax an extra action, then it could become quite challenging. I did test that it’s beatable with no equipment and without fighting the extra monsters out on the mountain and the bonus monster in the innermost cave, but I didn’t check if it’s beatable without Marge.