Holts acquired Glen Line in 1935 at a bargain price due to the collapse of Royal Mail Group. Glen & Shire Lines were allowed to keep their identity because of the benefits derived from the conference system andaccess to the east coast, they kept some of their agents out east. eg Bousteads & Jardine Matheson. Richard Holt became Chairman of Glen Line but kept two of Glens Managers on.After that Holts ordered new ships for Glen designed by Harry Flett and were responsible for manning. Glen Line had British Officers and Chinese crew ie: Stewards, Petty Officers Ab's,greasers etc.
My father's first ship as a Midshipman was on the Glenbeg which he joined in 1940 at Birkenhead and he continued to alternate on Glen ships and Bluey's until he became master in 1962 after that he only comanded Blue Funnel Ships. From his point of view Blue Funnel & Glen where one and the same and its plane to see that ultimate control was exercised from India Buildings but Glen had some autonomy at operational level in London. So both sides of this "discussion" can claim to be right.