Technical Indicators ; Stochastics & RSI

When it comes to trading with technicals, an indicator can give a particular reading which 2 people can see however it could be a buy/long from one persons perception/interpretation and a sell/short signal from another’s yet seeing the same indicator. To everyone’s understanding the top and bottom lines on these indicators (80:20 and 70:30) represents oversold and overbought. There are different teachings however on what they mean. With Stochastics, with these parameters (3,5,2) I have learnt/be taught that when combined with a SMA line of a 50 period, if above the line and in the overbought sections (80 on Stochastic or 70 on RSI) you buy as it is a momentum indicator representing the strength, however I’m aware that some people are educated/made to sell when overbought and I just wanted to see different opinions and views on the matter.