Here are the stats for the three players in question (Hansen, Barton, TakiTaki) this year. Keep in mind that Hansen and Barton got theirs against the Sagarin #17 schedule and TakiTaki got his against the #69 schedule:
Hansen: 88 tackles, 19 TFL, 5 sacks, 2 INT, 3 PBU, 1 FR
Barton: 92 tackles, 10.5 TFL, 3.5 sacks, 1 INT, 5 PBU, 1 FF
TakiTaki: 89 tackles, 9 TFL, 3 sacks, 3 PBU, 1 FF
Takitaki has similar (but slightly worse) stats, despite being clearly the best player on your defense, against a weak schedule. Barton and Hansen would absolutely start over him.