The great practical advantage of the Indian consonant order is that it is not arbitrary, so it does not have to be memorised cell by cell. Learn that the rows run velar, palatal, retroflex, dental, labial, and that within each row the order is plain voiceless, aspirated voiceless, plain voiced, aspirated voiced, nasal, and the whole of the chart follows.
Ka is the anchor for that scheme, and a reader who wants to find any of the other twenty four stops counts rows and columns from it. This holds across the entire Brahmic family, which is why someone who has learnt the order in one script can navigate a chart of another almost immediately, including a chart of Ranjana. It is also why the correspondence between Ranjana and Devanagari can be stated letter for letter with confidence: the two scripts write the same inherited series in the same inherited order, and only the drawing differs. For an unencoded script that consistency is more than a convenience. It is the main reason a Ranjana chart can be checked at all, since the position of a letter in the order is a fact independent of any typeface, any encoding and any individual scribe's hand, and it survives where more fragile evidence does not.