Traffic grooming continues to be a rich area of research in WDM optical networks. In this paper, we identify four kinds of path level traffic aggregation/grooming strategies - point to point (P2P), point to multi-point (P2MP), multi-point to point (MP2P), and multi-point to multi-point (MP2MP). We develop an auxiliary graph based approach as a generic network dimensioning solution for these architectures. Using our model, we compare the performance of various architectures employing path level aggregation in both single hop and multi-hop scenarios. For the studied scenarios, we observe the following - (1) MP2MP outperforms other architectures by multiple orders of magnitude in single hop networks, (2) P2P performs the best in multi-hop transceiver constrained scenarios, and (3) P2MP performs the best in multi-hop wavelength constrained scenarios.