Migrating ios codebase with multiple targets from swift 2.3 to swift 3 latest version

Question

I have recently started migrating my ios app from swift 2.3 codebase to swift 3 latest version. My app has 3 different targets. When I tried converting the swift sources in all 3 targets together, the diff showed more than 100 file changes. I follow the bitbucket code review process and 100 file changes made my Pull request very large & difficult to review. So I am thinking of converting target 1 swift source first, get it it reviewed by my peers, merging it to develop and then doing the same for other 2 targets. Is it possible to have target 1 point to swift 3 whereas other 2 targets still point to older swift version 2.3. I know in my targets build settings, setting "use swift legacy language version" to YES will enable that target to compile using swift older version (swift 2.3 in my case) whereas setting it to NO will force that target sources to compile on swift 3. So if I set this setting to NO for target 1 and enable it for other 2 targets, will that be enough to achieve the purpose or do I need to change some other settings ?? Thanks