I think that masters/bachelor students should be able to handle that work. A new grant mechanism for masters/bachelor training grants that fund replication would get the job done with a lot of nice side effects.
It would be hard to know if the man on the line is doing it right, but you might get the benefit of accidental insights.
The obstacle there isn't what level of training researcher has (as long as it's sufficient), but who is going to pay for it.
At the scale proposed (a 6-fold greater number of mice per experiment than is usual) the cost of testing only the core hypothesis is easily over $100K. In addition there is the time involved, which can be from months to years, depending on the experiment.
Even scaling-up mice experiments would be quite costly, and beyond the size of most research grants. There would have to be new funding mechanisms in place for work like this.
The article proposes that this would be more economical in the long run, and so the NIH et al. should be in its favor. Perhaps they will create a new facility for just such work? Though that seems unlikely in the current funding climate.