I assume allowing us to pick the first territory earned in CW map would create some additional fun, compared with randomly assigning them. It would be OK to assign following territories in its nearby place as how the rule currently goes.
I think it has no impact on the actual rule of the game at all, and seems to be technically not hard to realize?

Yes!

I'd like to add to this, founder main colour should be the clan colour. :3

Great idea ... gives a bit of clan personal touch.

I like this idea! :)

Plus it could make things fun and competitive. E.g., if you start right next to your rival clan.

it doesn't matter does it? like at the end you could take any territory not just those adjacent. map doesn't actually do anything

Just another little nice aspect.

Rival (and friendly) clans being next to each other.

Yeah map is just a near-meaningless visualization. At the end of Clan Wars you can get the same results by just ranking clans in terms of # of wins. The only place where the map matters is that Clan Wars ends when the last territory has been conquered. You could even change the territory rewards to just be in terms of # of wins and they would work the same way.

Still, it's very nice if we could make the positions of clans on the map less random and more meaningful. The fact that Clan Wars has a map... with all this promise to it... makes me suspect Fizzer has something else planned though, that will be on top of the map. Looking forward to the surprise update where we find out what that is.

Fizzer said on stream that he lets clans start from different locations, so that how linked their territories are shows how a clan progressed. I really like that idea, but allowing people to pick their starts would break it.

I'm a lot more in favor of what Kratt suggested ("I'd like to add to this, founder main colour should be the clan colour.") I think having clans pick their color would be really nice.

`I think having clans pick their color would be really nice. `

This already is a thing. Your clan color is the most used color among your members, unless it's already taken by another clan on the map.