Have to ask: Is this like Haven and Hearth, and Salem, where a handful of trolls can destroy months of work in under an hour?
People could destroy a lot of work in under an hour. They would do so by slaughtering all your settlers, some of whom have good stats/equipment/levels. It has happened surprisingly little in the five months the world has existed so far.
It feels significantly less hardcore than H&H/Salem, though I never played those games enough to understand just how quickly/slowly an alt could be leveled up. When my mid-level character in H&H was murdered I just quit; despite having a small walled-in settlement where I could've regrown a character. I could definitely see a 2-4 month old player quitting LoL if all their settlers got killed.
It would take a very, very concerted effort to flat out destroy someone in LoL once they have walls up. There are also a lot of ways for someone to fight back/make that destruction painful on the aggressor. And the destruction would take days/weeks so the aggressor would have to put their troops at risk of being counterattacked.
There is a middle ground where you can be force vassalized by an aggressor. They could potentially destroy your military and tax you 10% daily. But again in that scenario you have ways to hurt them/their friends while they have you under forced vassalization.
The gap between the strongest character and a serious mid-tier character in H&H/Salem was always massive. Not so in LoL. A mid-tier house can really hurt a top-tier house; a small kingdom can (and has) beat a large one in a war.
Perhaps due to some of these factors, the original French playerbase was surprisingly passive. They didn't leverage their advantage and subjugate everyone. They were also polite about war - giving warning ahead of time rather than doing surprise slaughterings while their opponents slept. I give them a lot of credit for allowing the game to grow in a healthy/peaceful way. Now other groups/nationalities have caught up so the dynamic might change - on the other hand, several people have completed their walls.