Multi-sensor strategies are key to the real-time determination of Eruptive Source Parameters (ESPs) of explosive eruptions necessary to forecast tephra dispersal and deposition accurately. In order to explore the capacity of these strategies in various eruptive conditions, we analyze data acquired by two Doppler radars, ground- and satellite-based infrared sensors, one infrasound array, visible video-monitoring cameras as well as data from tephra-fallout deposits associated with a weak and a strong paroxysmal event at Mount Etna (Italy). We find that the different sensors provide complementary observations that should be critically analyzed and combined to provide comprehensive estimates of ESPs. First, all measurements of plume height agree during the strong paroxysmal activity considered, whereas larger discrepancies are found for the weak paroxysm due to rapid plume and cloud dilution. Second, the event duration, key to convert the Total Erupted Mass (TEM) in Mass Eruption Rate (MER) and vice versa, varies depending on the sensor used, providing information on different phases of the paroxysm (i.e. lava fountain, lava fountain-fed tephra plume, waning phase associated with plume and cloud expansion in the atmosphere). Third, the derived average TEM agrees among all sensors for both weak and strong paroxysms. Finally, given that unfortunately no existing strategy or combination of strategies can provide information on the Total Grain-Size Distributions in real time, a combination of grainsize data from both tephra-fallout deposits and satellite retrievals is recommended to provide an accurate description of past eruptions to be used as a proxy for real-team tephra dispersal forecasting.