I have three groups of users $-$ $G1$, $G2$ and $Control$. The users in each of these three groups are different but are carefully selected and have similar properties. I treat each group with a unique treatment. $G1$ is treated by $T1$, $G2$ is treated by $T2$ and the $Control$ group is not treated at all. For each of these groups, I measure a variable $X$ before the treatment and after the treatment. I have the following questions -
 I would like to measure if my treatment (both $T1$ and $T2$) made a difference. In this case, I need to compare the variable $X$ for users in groups $G1 + G2$ to $Control$. Since I do not have any knowledge of the underlying distribution of data, I plan to use a Wilcoxon Signed Rank Test. Is this correct? If not, which other test would be appropriate?
 I want to measure which of the two treatments ($T1$ or $T2$) performed better. How do I do this? Should I perform a statistical test between users in $G1$ and $G2$ OR perform a statistical test between $G1$ and $Control$ AND $G2$ and $Control$ and interpret from the corresponding result?