Yet another 2*->3* transitioner looking for roster advice

So I have a quick question. I’m currently sitting in a 2*-3* transition phase. Here’s my current roster (Which I proudly can say I have accumulated without investing a single dime as of yet)

2*
Ares (4/4/5)
OBW(3/5/5)
Captain Marvel(3/5/5)
Daken(4/4/5)
Modern Hawkeye(3/5/5)
MN Magneto(3/5/5)
CStorm(5/5/3)
MN Thor(3/5/5)
Wolvie(5/5/3)
Johnny Storm(4/2/5 only @ lvl 86)

3*
Hood(lvl 104 5/2/1)
Steve Rogers(lvl 102 2/4/2)
Daredevil(lvl 102 3/3/2)
Hulk(lvl 102 4/2/2)
16 others below lvl 80

4*
Invisible Woman (lvl 86 2Y)
Devil Dino(lvl 78 1/1/1/)
X-Force Wolive(lvl 78 1/1/1)
Thor Goddess(lvl 70 1Y)

My question is this…I currently have enough HP to open a 36th roster spot. I have the following covers in limbo

Starlord(Purple)
Scarlet Witch (Blue)
IM40 (1 Red, 2 Yellow)

Should I use my HP (I have a total of 675 availble) to open a new roster spot for any of the above, and if so which one, and if not what should I better use my HP For?