The Guard attained their peak stats in masters 1, the matches after their masters 1 first seed games have been underwhelming with no memorable insane plays, they have been underwhelming in NA qualifiers for masters berlin as well, if you look at how FaZe or NRG played, they were insanely hard to beat/memorable gameplays, The Guard games have been very underwhelming mainly because everyone didn't peak in their roles.
If addition of shroud to sentinels is perfect fit for team chemistry, its going to be an easy first map win for sentinels, the second map cloud 9 is also not a GREAT team right now in their previous form, idk how much they've improved, but imagining their previous forms, I think sentinels can beat them as well.
only teams that can destroy sentinels are FaZe and NRG, which i think they would definitely do it unless sentinels play damn dominant than we expect which i think is not possible in a limited practice time period.