The perils of premature domination

[Jacobin]

Just finished a Shimazu legendary domination campaign in 1577 - way earlier than any previous campaign.



This left me feeling strangely flat and unsatisfied - all my victories were achieved with armies made up almost entirely of ashigaru (I don't think I recruited more than half a dozen samurai units in the whole campaign and all but one were still alive at the end), I never even got the chance to recruit legendary geishas or hero units or maxed out warrior monks, never built a citadel, never went bankrupt, never had to fight epic battles with 4 or 5 enemy stacks etc.

I don't use any exploits, only camp in desperate battles where I am hugely outnumbered have no escape and just want to inflict maximum damage, only start using agents really aggressively when I have captured the Ninja provinces in the centre, don't use nanban trade ships as historically I don't think any playable clan other than perhaps the Oda should be able to convert to Christianity, etc

So what else can I do to slow things down for my next campaign which will be as the Mori? - spend 20 years on the edge of Realm Divide teching up, buying every building upgrade and building uber-samurai stacks? campaign as a peacenik faction and only attack rebels and clans that attack me first (which would work historically for the Mori - if Eiji Yoshikawa's Hideyoshi novel is to be believed Mori Motonari admonished his sons to never expand beyond the west of Honshu), find a mod that speeds up research?