Recognize possible strain by seedling?

Hey I'm a first time grower who germinated bagseeds and planted them all in a pot. I have no way of knowing which seeds were which but I know that some came from piff and some came from regs. I wanted to post these pics of these 2 that just sprouted cause they look to be diff strains and I wanted to know if anything could be told by them at this point.

I notice the younger plant (about 2 days younger) is taller than the older one. does that mean anything? Perhaps a male? Also the stem is thicker.

kinda funny... just like me...

bag seeds are some weird things...

first two pics are of seedling planted 1 week after the last 2 pics seedling...

btw i wouldnt plant them together so close.. in the same pot.. when they get bigger roots will be interlocked and if u get a male or need to transplant gl getting roots apart and all..

just put a plant in its own pot, kinda makes it ezier for future things..

most of reg is indica... and telling what strain at this stage is pretty impossible. first pic two day old 2. 4 week 3 day