Newbie question about the speed of the network in 2025.

Suppose I want to monitor with a bot a given long dormant address A, so that if it sends a transactions to some other address B, say tomorrow at 10:09:26,  then my bot will also send a transaction to B at the same exact time,so that in the blockchain it is impossible to say which one is earliest.

Is it possible? Can you expnain the mechanism, including the time it takes for a tx to be accepeted. Thank you.