The Commercial Diver Network
Absolutely correct, professional diving should been done by means of a proper umbilical, comms, bail-out and preferably CCTV.
In this case a 5 man team is much better to deal with the situation in case of emergencies.
If the standby needs to go in, then there are two tenders available (one for each diver) and a supervisor who can coordinate all the required actions.
Otherwise: one man (the supervisor) must tender two umbilicals and operate the comms.
It is obvious that a 5 man team is much safer. And if forced by law to work this way: who’s gone complain? Safer working means in average that there are more people (more jobs) involved as wel.