Three subs, one combat?

I have a sub with 54 drillers, followed by another sub with 0 driller+Martyr, approx 10 minutes after.
I encounter an enemy sub with 2 drillers. Martyr dies...
How come the 2 enemy driller sub isn't neutralised by my 54 driller sub? I need my Martyr to survive!
Or is it a bug of the Time machine preview?
I encounter an enemy sub with 2 drillers. Martyr dies...

How come the 2 enemy driller sub isn't neutralised by my 54 driller sub? I need my Martyr to survive!
Or is it a bug of the Time machine preview?