I'm not sure that tying the amount of good's you can carry to your troop amount makes any sense. Surely you should be able to carry as many as you want because the risk is if you get attacked you are screwed as such? Otherwise the gold making process is going to be hellishly slow and there's no real point in going long distances to trade, because the amount you earn from trading far off will probably be less than the amount you could have gained from crafting and just sitting there. Add on the fact you'd be paying upkeep for troops if you wanted to carry more, and you have no incentive to trade over long distances at all.
I vote for the ability to have trade caravans with 0 protection. No limitation at all on the amount of goods you can carry to trade.
For this + the too much micro complaints, it kind of depends on the balance, tweaking to make it worth it especially for large scale trading (profits - (time wasted+ management hassle+troop recruitment/upkeep costs)).
It looks like chadz' goal is to get a lot of large caravans in play, travelling inter-city routes, which is why cities are now marketplace hubs collecting production from smaller traders running out of local villages. Meanwhile larger clans/alliances (presumably larger clans will have people who ENJOY playing the micro game, to manage it all) will be operating inter-city trading routes between these hubs, and sending big 100-500 (or more?) troop sized caravans around between cities moving large scale volumes of goods across the map. The end result will be a lot more high value targets criss-crossing the map, so there's all kinds of battles taking place beyond the village CTF fest of Strat v2.0.
This is all in all a great idea and adding a lot of depth and more battles to strategus. It seems a bit intimidating since it is poorly explained and we all have nothing and are stuck on rivers but I think once the trade system gets rolling it will really add a lot.