This study employs molecular dynamics simulations to unravel the interplay between twin spacing, temperature, and mechanical response in nanotwinned AgPd alloys. For fine-grained systems, a dual strengthening-softening transition emerges as twin spacing decreases, driven by a shift in dislocation behavior from inclined-to-twin-boundary slip to parallel-to-twin-boundary glide. In contrast, coarse-grained configurations exhibit monotonic strengthening with reduced twin spacing, governed by strain localization at grain boundaries and suppressed dislocation activity. Notably, cryogenic conditions stabilize pre-existing and nascent twins, whereas elevated temperatures intensify atomic mobility and boundary migration, accelerating twin boundary annihilation ("detwinning").