They signify progress, based on the eradication of certain kilesas...
In line with your question, it would be interesting to know if certain kilesas could be removed in an alternative sequence. For example, could you eradicate Sloth before Worry?
"Do not force others, including children, by any means whatsoever, to adopt your views, whether by authority, threat, money, propaganda, or even education." - Ven. Thich Nhat Hanh
"The uprooting of identity is seen by the noble ones as pleasurable; but this contradicts what the whole world sees." (Snp 3.12)
"To argue with a person who has renounced the use of reason is like administering medicine to the dead" - Thomas Paine