A combination present in a chart is not for that reason active in a life, and the Raja yogas are where the distinction matters most, because they are the combinations popular writing is most eager to find. The classical position is that a yoga produces its result during the planetary period, the dasha or the subperiod, of a planet involved in forming it, and not otherwise.
The Vimshottari dasha system, the standard scheme in North Indian practice, assigns fixed periods to the nine grahas across a notional 120-year span, so a given planet's major period may fall in youth, in old age, or not within a life at all. A Raja yoga formed by planets whose periods never arrive is, on the classical view, a yoga that never operates.
The tradition adds a second qualification, yoga bhanga, the breaking of a yoga, in which a combination otherwise well formed is undone by the affliction of the planets that make it or by their placement in the sixth, eighth or twelfth houses. Taken together the two conditions mean the class is read as a potential to be timed and tested rather than as a promise, and the atlas describes it in those terms rather than offering it as guidance.
One further point separates the classical treatment from popular summaries. A Raja yoga is not a claim about rulership in the literal sense, whatever the name suggests, and the handbooks apply the class to standing, office and recognition across every kind of life. Reading the label as a prediction of kingship is a misreading of a technical term, and it is the sort of misreading that a translated word invites.