SUPREME CONSIDERATION IS SPEED

On one side, there would be people claiming that he is the usurper and wanted to oust him form the throne. On the other, there is external enemies coming in.

Is it not the throne a seat of thorns? Who would want to sit in such a throne?

This all plays out like this, always.

it did not only happen in war. It also happens in other situations in life.

There are many disadvantages of being first of taking the crown of Veranis in the current situation.

 For other generals, if they raise the banner of wanting to oust an illegitimate heir to the throne, putting himself on the right cause, possessing the higher moral ground, he would then easily take the throne later. 

And the rule and order of such a person is also would likely be more stable than the one who come first