I agree that there are still gaps, I guess I didn't think we were talking about the entire NH lineup here. I also agree with a little more reading that the Boomer 20 and 25 are Class I tractors not subcompacts. At the same time, they may fit the bill for the OP.
Frame size on the NH Boomer 20 and 25 will be larger than the Deere models you stated above, otherwise the hp and other specs are comparable.
NH
Mitsubishi S3L2 3 Cyl. Diesel Engine
27.0 Gross Engine hp @ 2700 rpm
19.9 PTO hp @ 2700 rpm (HST)
80.4 cu. in. (1.3L) Displacement
1433 lb. (650 kg)
Tier 4a compliant
Turn-Buckle Type Leveling Mechanism
Naturally Aspirated
Chain Stabilizers
Under Hood Muffler / Exhaust
Fixed Link Ends
Single Element Air Cleaner
Full-flow, Spin-on Oil Filter
ROPS
6.6 gallon (25L) Fuel Tank
2-Post, Foldable Roll Bar
JD
MODEL 1026R
Engine
Manufacturer Yanmar 3TNV76
Engine HP (kW) - gross 25.2 (18.5) per ISO 97/68/EC
PTO HP (kW) - Gear transmission ---
PTO HP (kW) - Hydrostatic transmission 18 (13.4) per SAE
Rated engine speed, rpm 3200
Type Diesel
Operating range 1360-3370
Aspiration Natural
Cylinders/Displacement, cu. in. (liters) 3 / 68 (1.115)
Bore and Stroke, mm (in.) 76x82 (2.99x3.23)
Air Cleaner Dry type with safety element
Fuel Tank Cap., US Gal. (L) (Open; Cab) 5.6 (21.2)
Hydraulics Type Open Center
Pump Rated Output, gpm (L/min.) 6.3 (24)
Steering 2.8 (10.8)
Implement 3.5 (13.2)
Pump Type Gear
Maximum Operating Pressure (PSI) 2000