How many people die each year from flu worldwide? How many times mortality of Covid-19 is bigger?
Asymptomatic cases are extremely rare, if they infects multiple others, they will likely be identified through retrospection. Overall, I'd say those cases are unlikely to result in significant difference in the estimate.
This is likely exacerbated by many countries not having ready access to flu vaccines and/or proper hospitalization for those that need it.
Compare this to America-specific numbers, where 34,000,000 – 49,000,000 Americans catch a flu-related illness each year, yet only 20,000 – 52,000 result in death [2].
[1] https://www.cdc.gov/media/releases/2017/p1213-flu-death-esti...
[2] https://www.cdc.gov/flu/about/burden/preliminary-in-season-e...
So, 1.3-1.9 million US deaths.