Observations of young multiple star systems find a bimodal distribution in companion frequency and separation. The origin of these peaks have often been attributed to binary formation via core and disc-fragmentation. However, theory and simulations suggests that young stellar systems that form via core-fragmentation undergo significant orbital evolution. Using simulations of star formation in giant molecular clouds we investigate the influence of environment on multiple star formation pathways and the contribution of core-fragmentation on the formation of close ($<100\au$) binaries. Simulations are run with the adaptive mesh refinement code \texttt{RAMSES} with sufficient resolution to resolve core-fragmentation beyond $400\au$ and dynamical evolution down to $16.6\au$, but without the possibility of resolving disc-fragmentation. We find that star formation in lower gas density environments is more clustered, but despite this, the fractions of systems that form via dynamical capture and core-fragmentation are broadly consistent at $\sim$40\% and $\sim$60\% respectively. We then compared the simulation with conditions most similar to the Perseus star forming region to determine whether the bimodal distribution observed by Tobin et al (2016) can be replicated. We find that it can be replicated, but it is sensitive to the evolutionary state of the simulation. Our results indicate that a significant number of binary star systems with separations $<100\au$ can be produced via non-disc-fragmentation pathways due to efficient inspiral, suggesting disc-fragmentation is not the dominant formation pathway for low-mass close binaries in nature.