Erit verendum mihi (In Catilinam 1)

The Latin sentence in question is:

"si te iam, Catilina, comprehendi, si interfici iussero, credo, erit verendum mihi, ne non potius hoc omnes boni serius a me quam quisquam crudelius factum esse dicat"

It seems to me that this should mean something like this in English:

"Catiline, if I now were to order your arrest, if I ordered your execution, I believe my source of fear would be not so much that the honest would complain I had acted late, but rather that someone would claim I had been too severe."

But one of the translations in front of me, from Penguin Classics, seems to say the opposite:

"If, therefore, Catilina, I order your arrest and execution, surely all honest men will complain, not that I am acting with undue brutality; but that I have delayed too long."

Which of these is the correct translation?

Imber Ranae

Ranunculus Iracundus
Both your and the Penguin translations miss the mark because they entirely neglect the gerundive clause erit verendum mihi, which introduces the fear clause starting with ne. Maybe the penguin translator felt (wrongly, in my view) that the nuance of the fear clause wasn't important, but if you want to have a complete understanding of the sentence's grammar you should try to translate more literally. So it's not 'I believe...will/would complain', but rather 'I'll have to fear/worry, I suppose, that...will/may say') The tricky part is the non potius...quam, which literally means 'no more X than Y', but it can be rendered more intelligibly in English as 'no less Y than X' or 'just as much Y as X'.