Use full differential amplifier with gain less than 1 AD8139 or ADA4932-1

I'm planning to use AD8139 or ADA4932-1 to drive AD9236. And I want to do x10 attenuation at the same time. I've some guestions:

1. The ADA4932-1 gives Figure 39, "Open-Loop Gain and Phase vs. Frequency", The phase margin is aboult 45 degree, so is this the 'proof' of 'Can be used with gains less than 1' ?
2. May AD8139 be used with gain less than 1, such as 1/10.

Thanks