I just realised, if you are going to eliminate the whole backstory of Grievous collecting lightsabers, at the begining of the movie when he captures Obi-Wan and Anakin there is the dialogue:

_Your lightsabers will make a fine adition to my collection

_Not this time, and this time you wont escape.

You take out the line of Grievous (so he is just disarming them, not collecting lightsabers), but you have there a great oportunity for adding a good line. A good line that has to be answered with a "Not this time, and this time you wont escape". Helping that idea of Obi-Wan and Grievous having a backstory of fights. You know... something like:

_Finally! (S02E10) The story of Obi Wan Kenobi ends here... (S02E09)

_Not this time, and this time you wont escape.

Also, on that same episode (S02E09 Grievous Intrigue) you have the lines "Kenobi! What a surprise! I supose you came here to bring me to "justice"", "So, Kenobi, is everything going as planned?", "You wouldnt come here without a plan, and you wouldnt come here alone" Wich might be useful for Utapau.