How strong were the androids 17 & 18 in piccolo's mind?

[Miss Scarlet]

Piccolo thinks that because vegeta surpassed goku he can take care of the androids:

Spoiler

Of course, afterwards (when the androids defeated them) he said he didn't expect them to be that strong:

Spoiler

I think he expected them to be above trunks, but weaker than goku or vegeta. What do you think?

 

[Spiral-Force]

It's tough. Prior to Vegeta blasting off, no one was like "Vegeta's got this", but coming out the victor against 3 fighters suggests a notable difference. SSJ Vegeta -- at that stage -- had yet to be tested in an all-out gruelling battle, so there was still room for the idea that there might be merit to his confidence. Overall, I think Piccolo didn't have a decisive scale in mind, but sought the more hopeful possibility.