Good info I love this game Great idea using 4 nurses for a beginner against someone who has already learned to play
Necessary, absolutely not. There are many strategies based on the number of nurses, and the 3-nurses strategy (meaning no new nurse at all during the game) is probably one of my favorite but quite unforgiving. You will discover that starting at 4 nurses (and I tested this) will take off one part of the tension which is crucial in Myrmes.
Now as a first game variant (start at 4 nurses) or to put a handicap to experienced players (who start at 3 nurses) against beginners (4 nurses), why not?
I'm myself into something else, when explaining, with a simple advice: "first objective: do your first nurse and first level of colony the first year. forget about objectives for now (worry only beginning of second year, do them last year)." This is not the best advice for the variety (but if I'm in the game, I will try more exotic strategies), but good to enjoy the very first game, which indeed can be quite frustrating.
As told by RoadHouse above, until you reach the winning at scoring of 75-85 points range (on a general idea), you have to still learn things from the game. But this can be quite enjoyable before that (winning with 40 points the first is not unusual), just that you have more to discover/dig. And to have the envy to dig, not frustrating the players is an important goal
So I would say it's up to you and your group.