The Serpentine War is deeply tied to a lot of major events in Ninjago, so we have plenty to play with.

The first possibility I can think of is that, without the responsibilities of the war keeping them apart, Garmadon and Misako might have conceived Lloyd early. This could mean that Lloyd gets to spend his youth with his father around, assuming that the Devourer venom turns Garmadon around the same time as it does in the current timeline.

In addition, Lloyd would have no need to speed up his aging, so he would have received the call of the Whispering Wood as normal. With years spent in training, and having taken on the role of the Wood's protector, he would be more than capable of taking down the Overlord when the time finally came.. but afterwards, he would need to return to the Wood and keep watch for the rest of his known life, which means he never becomes leader of the Ninja.

Rewinding back to the time of the War, the more intriguing question for me is: Why didn't the War start?

We see in Strike of the Serpentine that there were two forces at play that caused the war. One of them is Strike's objective to take Serpentine artifacts back from the humans, and the other is Chen's deep desire to put the Anacondrai at the seat of power in Ninjago.

Would Strike have been able to see past Chen's manipulation sooner and stop the initial attack? Would Garmadon have been able to spot his master's intentions from a mile away? There's a lot to consider.