If the manual tells you to approach at 1.4Vs, for example, then OK. But if the manuals recommends 1.3 and your airclub 1.6, what then ?
Simple, you fly the aeroplane in accordance with the POH/AFM. No one including flying/schools/clubs or any other "operator" have the right to demand anything different. When differences are demanded they are usually based on ignorance, hearsay and the thoughtless but well honed " that's what we've always done here".