I haven't actually altered such an instruction, but I would have thought forward runs 'often' was the default setting for a striker.
If not, I wouldn't go overboard with it, and to maintain balance, would set one 'often' and one 'rarely'.
It does of course, depend on the attributes of the strikers.
Delfuenso as far as I'm aware, is more of a predatory striker looking to get in behind defenses; Marquinhos is a creative link-up player; and Laurito is a tall, potentially target man striker.
I think - this is if the above mentioned is correct - Delfuenso would be best suited to making forward runs due to his goalscoring style, whilst Marquinhos would be best suited to sitting back and creating.
This is just my view, I think the best way to check it out is to try it in friendlies or against weaker opposition.
Best of luck.