I found a nice Colemak variant @ patorjk.com (you know, the site that let's you easily calculate different keyboard layouts. And yes, one can debate about the used weiging factors, algorithms etc.)   The variant I found is called Acemak 1.  It is as follows:

qwdpyfuk;
asrtghneio
zxcvblm

It is by a German guy (look the name up at patorjk 's site). I tested it with my typical use: 2/3 Dutch language, 1/3 English. And it scored clearly better than stock Colemak.  This might be a good variant for germanic languages in general.

Dutch freqs are like this:

e    18,91
n    10,03
a    7,49
t    6,79
i    6,5
r    6,41
o    6,06
d    5,93
s    3,73
l    3,57
g    3,4
v    2,85
h    2,38
k    2,25
m    2,21
u    1,99
b    1,58
p    1,57
w    1,52
j    1,46
z    1,39
c    1,24
f    0,81
x    0,04
y    0,04
q    0,01

DIAGRAMS
en    4,7
de    3,34
er    2,72
an    2,57
ge    2,13
nd    2,12
te    1,91
in    1,66
ee    1,65
el    1,37

TRIGRAMS
van    1
gen    0,99
den    0,84
een    0,74
ent    0,72
nge    0,7
ver    0,7
and    0,67
end    0,63
ten    0,61

I can see why it scores well. The d is typed with the middle finger. That place on the top row has near home row quality, it is too good for the f.   Also, the l is in a better place. The digram el is quite common and is easier to type like this. The g is in a better place as well.  And still, it manages to be good enough for English (I think). of course, there are no free lunches, so it _will_ have draw backs.....

I will try it out the coming weeks.