In general, if the waiters are getting market compensation per hour or even lower, then they should be able to split the gratuities among themselves or keep the gratuities individually whatever the arrangement is at a given restaurant. On the other hand,  if the employees may be working without INS authorization, then they might have the lower hand in deciding the compensation structure. In that case, the employees should be just grateful that they have jobs.

On the part of the customer/guest the recommended tip is between 10%-20% of the subtotal without tax added. At eateries where service is reviewed poorly but the food is above average, I have, at times, mulled over paying the tips in advance so that I would get an acceptable service throughout the service experience.

In any industry esp. in hospitality industry, if the employer allows the waiters to keep the tips it directly result in a more caring customer service which in turn will encourage returning patrons.