Both are not mutually exclusive.
If u got in at a market high, u need to spend a longer time in market to earn the MOS ( margin of safety), if u timed in correctly, u are less at risk leaving the portfolio to gain dividends. If u are able to get baggers, u can profit take and it became zero risk, until u put the money into use again.
CW call it trading around core positions.
Doesn't matter the semantics, the important part is portfolio allocation into Cash or other equivalent asset class. The percentage of which is trial and error, until u find one that works.
But either way, u need to need some FA knowledge. Seriously, if u listen to Gurus talking about TA, like Gupta, ( not sure I get it correctly ), I think he can shame many FA wannabes with his analysis of macro themes. He just didn't box himself in semantics. Doing charts doesn't mean u are TA purist.
Most things come with 2 sides. Pick a side to start, not to stay. I guess is sound advice.