Which is absolutely true. If you had two otherwise identical clones beating on each other, with the only difference being one pumping perception at the cost of resolve, the high perception clone has the advantage - since all of their non-deflection targeting abilities would be more likely to land.
We can have a lively debate on the relative merits of the different pieces of defense - maybe +1 deflection is 90% as valuable as +1 accuracy in the clone war, maybe it's only 50% as valuable - but it's less valuable, in a vacuum, without question.
That doesn't necessarily translate to the rest of the game, where your fights are decidedly *not* otherwise mirror matches, and situational factors dominate. In a more general context, resolve is interesting in that it has both increasing returns and discontinuous jumps in effectiveness, giving you three clear optimal points to hit - maximum possible to get full increasing returns benefits, just enough to avoid incoming crits, and full dump.