In my designs, Dragons don’t grow to kaiju size, So Yak’s will always be taller and bigger. But they’re not short, but a warrior culture. So they all try to learn how to fight in case someone missuses magic. Eventually Spike and Twilight will consider that Spike’s better of having fighting skills of his own to keep himself and others safe since magic can be used by so many and tragically, there will be some bad apples in the mix. But due to where he was born and how he was raised, Spike’s fighting style can be unique compared to that of other dragons.

https://www.deviantart.com/cinnamon-swirls/art/Future-Spike-OLD-625587948

Here, Spike was trained to be a Royal Guard, resulting in him knowing how to fight and did a lot of good with that. Would Canon Spike have any fighting skill like that? Who would train him if he had gotten to know how to fight? Flash Sentry? Shining Armor? Rainbow Dash? Garble? Smolder? Ember? Torch?
Simply put, If Spike were to have fighting Skill, who trains him? And what sort of fighting skills would he have? Offence, defence or a balance between the 2?