Gibbs left for West Brom ahead of Oxlade-Chamberlain's departure for Liverpool.
"Ideally you want stability and you want players who carry the values for the generations," he said.
"Overall it's true that with Gibbs (it hurt) more than Chamberlain because he had been educated at Arsenal from the age of 10.
"When he arrived he was a left-winger. I transformed him into a full-back because he was not necessarily rated as a guy who would make it as a left winger but I saw something in him that was very intelligent, with pace, that made me feel he could make it as a left-back.
"Academy players carry the values that you think are important, which are based on mental qualities, humility, respect and commitment, and as well football qualities which means you always try to play in a positive way. Plus real team play and focusing on a collective way."