We've had a lot of changes happen in strat since the 3.0 map opened up, but lets focus on what makes this game actually fun for most people. The battles. They are what draw people to play crpg in the first place, and why they maybe then get interested in strat.
If in 2.0 I had to pick an average size for armies made for battle/sieges(not just moving dudes around)I would say around 2500 is a pretty good number. So with that in mind lets look at what it costs in 3.0 to equip that force.
2500 * 107.16(Studded Leather Coat) = 267,900
2500 * 31.76(Nasal Helmet) = 79,400
2500 * 11.56(Leather Gloves) = 28,900
2500 * 6.12(Sarranid Leather Boots) = 15,300
625 * 26.16(Falchion) = 16,350
800 * 30.04(Old Heater Shield) = 24,032
625 * 30.16(Two Handed Axe) = 18,850
625 * 5.08(Pitch Fork) = 3,175
625 * 34.84(Short Bow) = 21,775
1875 * 6.44(Arrows) = 12,000
Total: 487,682
That gear is about the bare minimum I would go to actually spend money on equipping people and expecting the gear to actually do any good. I suppose you could cut the boots, helms and gloves to save ~125,000. Also there are no catapults or anything. Maybe cut some more and just give everyone 2h axes and pitchforks and let them wear trash bags.
So how long is it going to take clans to start assaulting fiefs and stuff? Well I guess it depends on what the most profitable trade route is for your clan and how many people you have. If you have 50 people in your clan, it will take them each earning 266 gold every day for a month to make 400,000. You'll have to get the troops via magic because that is with all 50 going full for gold, 0 on recruiting.
Of course if you lose I imagine your clan will completely quit because no one is going to do that again.