CubeSats are small sized satellites constructed using commercial off-the-shelf components and weigh no more than 1.3 Kg. They are ideal as an educational tool as well as low-cost platforms for space research. A key advantage of CubeSats if their ability to form swarms. A fundamental problem, however, is maximizing the total downloaded data from a cubeSats swarm to ground stations. The key challenges include intermittent contact time and duration with ground stations, and limited resources. Henceforth, this paper aims to study data transmission policies from CubeSats to ground stations. Unlike prior works, we quantify the benefits of transferring data over Inter-Satellite Links (ISLs). We investigate four satellite-to-ground pairing rules: namely, pair Transmit Most Data, Random Pair, Shortest Contact Duration, and Round Robin. Our results indicate that ISLs help CUbeSats ensure they have more data to download to ground stations. Moreover, the use of ISLs simplifies s-g pairing because of the aforementioned rules can be used to yield similar amount of downloaded data.