One particularly prevalent structural health monitoring (SHM) technology advancing in aerospace structures is the use and analysis of Lamb waves to detect the presence of damage. While honeycomb-core sandwich structures are regularly used in aeronautical applications for their high strength-to-weight ratio; they present significant challenges for numerically simulating these waves. The complex geometry of the honeycomb core, coupled with the short wavelengths characteristic of Lamb waves required to detect microdamage, demands extremely fine discretisation making the simulation of wave propagation in these structures computationally costly. This paper presents an efficient modelling framework utilising the Carrera Unified Formulation (CUF) to address these computational constraints. By employing high-order expansion models, complex sandwich components can be modelled as 1D beams or 2D plates while maintaining global and local field accuracy. To further optimise the study, a layer-wise approach is investigated here where the honeycomb core is represented as a homogenised layer with equivalent material properties. This strategy significantly relaxes mesh requirements, enabling fast global wave propagation analyses. The study presented here examines the efficacy of this homogenised layer-wise model in capturing Lamb wave propagation across both the surface and the thickness of sandwich components. Results demonstrate that the combination of high-order CUF kinematics and core homogenisation provides a robust balance between accuracy and resource efficiency. This approach maintains high fidelity in predicting global wave behaviour while achieving substantial reduction in degrees of freedom compared to full-scale 3D models.