So they have actually created two distinct sets of testing for both officer aviation pathways? I would imagine there absolutely would be a large degree of overlap in requirements for both roles.
From the research I've done on the RAF testing (which I believe is what we've adapted/licensed), their tests are split into aptitude domains of:
verbal reasoning, numerical reasoning, spatial reasoning, work rate, attentional capability and psychomotor coordination. They test all 6 domains and then perform what they've defined to be an optimal weighting of each to give you your pilot/aco/jbac etc. score.
The only possible non-crossover domain for JBAC/ACO would be pyschomotor coordination (which isn't even the highest weighted domain for pilot in the RAF).
But I guess this is all needless speculation and I'll find out what's what in about a week. In my view it would be entirely pointless to perform worse on the mission elementary testing in some hope that it will put you in higher contention for a pilot OSB.