"From the Waikato point of view, we are probably looking at some of our All Blacks that we are paying significant amounts of money to and seeing that they are actually not playing many games for us," former Ireland and Wasps tactician Gatland told The New Zealand Herald.
"We worked out we were paying some of our All Blacks $50,000 (GBP 19,000) a game.
"That's going to put a lot of pressure back on the NZRU. That's the flaw in the system at the moment - you have centrally-contracted players but there are also two or three masters."
Lam, who led the Auks to the 2005 title with a squad weakened by call-ups to the national team, agreed.
"For us it actually is a lot easier that the All Blacks don't come back," he admitted.
"When they come back you have to chop and change - but now, whatever we start with, that is effectively what we've got.
"Certainly we'll miss the talent of the guys but, as a coach, you want to know what your boundaries are, who you have and then build."
The provincial coaches will find out which players they have at their disposal when the World Cup squad is announced in mid-July, just days ahead of the Air New Zealand Cup kick-off.