If I remember well, my original idea for the Longbowman was this :
Longbowmen (replaces Crossbowman) => I said Composite archer, but it is stupid
13

CP
24

RCP
Range (+1 range, -20 %

RCS)
Formation (+10 %

CS when defending in open terrain ; +25 %

CS against mounted/armored units)
=> With these promotions, the unit has as much CS as a CBM against most units at range (the +1 Range giving it a real edge though), but is more resistant when attacked, especially against cavalry units (the unit having around 17 CS when defending against these in open terrain), and inflict severe damages to cavalry when attacking.
=> The other attributes (cost, presence of "Formation II") aren't talked about here, since I just wanted to focus on the main idea that is giving the unit the "Formation" promotion : it would be the most simple solution I think, and we can always try to find something else if it doesn't work.
For the Hermitage, I was thinking about making it UW similar to the Great Cothon in how it breaks the codes by being available far earlier :
White Tower (replaces Hermitage)
Available at Chivalry (instead of Architecture)
Requires a Castle (instead of an Opera House)
Require 30
Citizens in empire
+5
CP
+2

Culture ; +1

Culture for every 4

Citizens in the city
+1
Culture to Castles (Hence the absence of culture boost above) ;
+3
Gold to Constabularies (so no upkeep for Constabularies in Empire) ;
+3
Food to Arsenals (slight bonus toward having more specialists in the Industrial era : synergizes with the UB1) => All these buildings are defense buildings (England, de facto, would benefit from an ersatz version of the Japanese UA by being incentivized to build defensive buildings in the mid-game).
-25 % Spy Stealing Rate on Empire (effective even in the Medieval era against civilizations picking Statecraft)
+1
Happiness for every Enemy Spy Killed (permanent)
Comes with 1 free
Artifact : The Crown Jewels (so bonus culture and tourism, hence once again the absence of bonus culture from pop. at that stage of the game)
Has 3

Great Work of Art/Artifact slots : +5

Gold
and +5
Culture when themed
It is quite similar to what was suggested previously, but with some twists so that it is a little less powerful, but comes earlier.
I don't think bonus for only one city is interesting enough : at the stages of the game where the four buildings involved become available, a few more yield won't do much difference, and the Grand Cothon already gives meaningful global bonus to some buildings while also being available earlier. I think that the number of buildings involved in the bonus of the White Tower should be decreased, the bonus changed, but the idea kept.