My parents have similar problems on their seven acres in a high-rainfall area, so I feel your pain.
And no they haven't taken my design advice-
mostly for the same reasons you've stated, but I'd suspect they're just being polite
Heavy liming helps a bit and mowing slows it down, but as you already know the only long-term solution is to improve the drainage.
An old
thread.
Here's what I'd do in my theoretrical 'if it was mine' plan:
choose an area to experiment on-say 500m2 with decent access (ideally road)
Map the contours (an A-frame level is
very basic to make/use)
choose/map a few low-lying areas that are on or near contour, keeping animal/human access in mind
If there's access to chipped tree mulch, bring as much in as ypossible (conifer's
fine)
pile where high-ground will be
dig mapped low areas into swales/interlinked ponds, preferably draining somewhere offsite
The swales/ponds don't need to be very deep at all
As you dig, throw the soil up onto the chip piles
Lime the high ground and sow heavily with clover, forbes and
local pasture grasses
Keep animals off for
ages
Easy in theory of
course!