In a trademark cancellation proceeding, can i just use the other side's "testimonial" evidence in lieu of providing my own?

I am a small business owner involved in a trademark cancellation proceeding against a large company. I believe i have a good case to show that the marks are not "confusingly" similar.

The large company took many depositions during their "testimonial" period. However, I have very limited funds to fight this matter and do not have the resources to take depositions etc...during my "testimonial" period.

My question is whether it is ok for me to just poke holes in the large company's testimonial evidence to make my case or do i have to present my own testimonial evidence to support my case? Of course, i realize that having my own testimonial evidence (e.g. depositions) is good but i guess i wanted to know what options i have to present my case on a shoe-string budget.

thank you.