(I've been travelling myself, thus the lack of input lately.)
CA -- companions choices in two groups: Rin and bandits; Us and the goblins + priest
Several reasons to pick the mining village.
1. The hills around them are absolutely the place to find more gobbos.
2. Probably better trades than the trading hub, actually, if only for grain convoys.
3. Remote location and therefore a better way to approach the capital without eyes on us.
4. Remote location and therefore a place ripe for shenanigans.
5. Maybe some side quests with the mines or whatever...
We are headed to the capital, so no need to go a smaller trading hub first, even if it is on the border. We already made enemies across the border so why get closer now? Only allows more eyes on us and more whispers before we reach the big city. That road between trading hub and capital will be watched and heavily trafficked.
Also, trading hubs tend to have lower prices because they are well-supplied in everything. I dispute that we would make more money with common goods in a trading hub. The mountain mining village is not well-supplied, and our cart full of grain that we will buy from the Erise villagers will do wonders in a hungry mountain town with little farmland.
(I see our cargo as mainly those things that we can get from Erise, furs from the goblin village, and the loot from our battle, which is mostly weapons and armour.)
Here's a devilish plan to get the most out of our trades in the mining town. I am thinking that we could create the perfect conditions to sell the grain and armaments from our battle to the mining town. The Barzams have already been raiding the area, so a little more raiding won't raise more alarms, and there's already rumours about who is doing the raiding. Let's send Rin ahead of us to harass the roads leading to the mining town, laying waste to a few caravans. We enter the town with grain and weapons when they need those things the most.
The local bandits are small potatoes, just local no-goods probably, who lack the leadership to attack better pickings than a sleepy farming village. Let's go do some diplomacy and get them to join us in a big hit on the mining town's trade routes. Tell them it's gonna be big, make them a fortune, and they'll mostly be there to look menacing and pick up the loot after Rin does the killing. They wear the gear that we got from the Barzam raids, looking like Galbady troops. They find an ambush site and make the mining town scared and a little concerned about food supplies. They gather a loot cache from picking off whatever caravans seem doable. Maybe even let some survivors escape to confirm that it is Barzam/Galbady at work.
We wait a few weeks after the hits begin, and carry grain and the less identifiably Galbady portions of the armaments into town with a squad of our gobbos, Runde, and the village priest. The gobbo squad is not a drain on our wagon load capacity. They march beside us on foot, with our goods and the few important people on the cart. If anything, get them to exercise by carrying even more grain sacks on their backs. We sell the grain and weapons that everyone in the mining town is panicked and eager to buy.
After we do business in the town, we can meet up with Rin again outside the town, and continue to the capital, paying off or killing the bandits that we recruited (silence is best imo)