Still not convinced with that goal tending duo and bottom 4 on defense but this should help. It's going to be tough to get a quality defenseman this deadline.
Honka for Trouba is a pretty lateral move to me. There are defenseman you can get to shore up Dallas' D, just depends what side you're looking for.
Then replace honka with the 2017 1st round pick and a lower prospect. There aren't many quality 2 way defenseman that are realistic trade options on either side.
Dallas Forwards are probably fine to force Ladd, and giving up Honka a first round draft pick and 2 second round draft picks is way to much for Trouba and forcing Ladd.