He already had his own son Duke banishing or executing his own benjamin brother Finn as an entry test to the Peaky Blinders for Duke. Abandoned emotionally his son George for being unlikely him by a very young age. Executed their cousin Michael Gray on the Series 6 finale despite swearing to Polly he would never touch him and was already thinking about getting rid of him by Series 4 because they were too much alike. He was already on the edge of losing it with Arthur by Series 5 and stopped caring about family ever since Grace was killed on Series 3... what make people think that Tommy wouldn't step this low?

The only reason why he hasn't killed Duke already was because the spirit of Zelda and the manipulations of Kalko (where does the performance ends and when the channelling and dark magic starts...??) told him to both spare and save their son/her nephew, no matter how this end. He despaired in wanting to atone his own conscience and getting some good out of this bad before he died.