Her strength is horrible. She has 15 STR after promotion, which seems fine, until you realize that she is Internal Level 18. For reference, 15 STR is the same as a 10/1 Wyvern Knight Lapis and 10/1 Tireur d'Elite Alcryst with his personal active. Both of them tie Timerra's STR while 8 levels lower and joining much earlier, early enough to grab pre-Chapter 10 skills.
Timerra's claim to fame is Sandstorm. It does significantly improve her damage, however due to her high IL she struggles to get it quickly. She needs the big EXP sinks from the paralogues, and other units want those. Moreover, Sandstorm is inconsistent. In a game like Engage, which uses reinforcements to enact time pressure, killing quickly and reliably is huge. Timerra can't do both without big resources that other units could use better. Also, Picket kinda sucks. It's lance locked and foot locked, which sucks, especially in comparison with other quality combat classes.
She also has some of the highest SPD+DEF stats in the game. Then again, her lead is not so big that it justifies her poor damage. I would rather take more damage or spend extra resources to kill enemies reliably on EP. And Engage does give you lots of resources to lower or nullify damage taken (Ike, Bonded Shield, Call Doubles, etc.).
I do not think that she is a F tier unit. She is more of a C tier to me. I do think she has a decent showing in Solm if you choose to deploy her, and her personal skill is great, but that's not enough to make her a high tier unit. What do you think?
TLDR: She has damage issues without an unreliable damage source, she joins late, her class is underwhelming, and she is not that good at enemy phasing.
