There has been limited modern scholarship about Sir Rowland Hill, which can be frustrating.
He was briefly discussed in the book The Gentry in England and Wales, 1500-1700 by Felicity Heal , Clive Holmes has some account of Hill as follows:
Not all parvenus exploited their purchases with the contempt for local values and personal reputation of the Sandys brothers; some very deliberately attempted to identify with traditional paternalist values. Sir Rowland Hill, a wealthy London merchant who purchased lands in his native Shropshire in the mid-sixteenth century, was a paragon among landlords: he ‘never raysed rennts… he suffryd the child to inioy the fathers farme before all others, he was the frynd of the widowe and fatherles’.
He is also discussed in Jones, I. (2017). The Governance of Shropshire During the Civil War and Interregnum 1642-1660. (Doctoral dissertation).
University of Chester, United Kingdom:
Sir Rowland Hill, who was born around 1492… He had become a wealthy merchant adventurer in London who probably traded in wool. He lent money to Henry VIII, and was deemed to be one of those who was ‘contented to forebear to another day’ so far as the King’s debts were concerned, and had been made lord mayor of London in 1549.117 Locally he was a JP, and was appointed to the Council in the Marches in 1551. Working through an agent, William Cotton, he purchased around seventeen manors mainly in the north of the county, between 1538 and 1559.
The Alan Bryson’s PhD Thesis -at St Andrews The Special Men in Every Sphere; The Edwardian Regime, 1547–1553 is also of interest.