In that first link I gave on 61st Div,
61st Infantry Division (United Kingdom) - Wikipedia, the free encyclopedia
It has these RA units.

• 119th Field Regt.
• 120th Field Regt.
• 145th (Buckingham and Berkshire Yeomanry) Field Regt.
• 63rd (Worcestershire and Oxfordshire Yeomanry)Anti-Tank Regt.

Which makes the 145th Feild Regt the Junior Regt.
RA 1939-45 145 Fld Rgt

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