Question: Are Naser Mestarihi and Justin Sane both singer-songwriters?

Context articles: Justin Bastard Sane
Anti-Flag
Justin Sane
1987 (Naser Mestarihi album)
Naser Mestarihi EP
A New Kind of Army
Life, Love and the Pursuit of Justice
List of Avenged Sevenfold members
Naser Mestarihi
Warped Tour 2005 Tour Compilation

Justin Bastard Sane (aka Justin Sane) is an American comic book creator, film director, puppeteer and animator.
 His comic books are done in a silhouette style reminiscent of early film and his movies feature sex, violence and satirical comedy.
Anti-Flag are an American  pop punk  band from Pittsburgh, Pennsylvania, United States.
 The band is well known for politically charged lyrics and activism, focusing on anti-war activism, anti-imperialism, class struggle, human rights, and various sociopolitical sentiments.
 The line-up includes singer/guitarist Justin Sane and drummer Pat Thetic, who founded the band; later members are guitarist Chris Head, and singer/bassist Chris Barker (#2) who replaced Jamie "Cock" Towns, who had replaced original bassist Andy Flag in 1997 following his departure one year prior.
 Anti-Flag is known also for their advocacy of progressive political action groups such as Greenpeace and Amnesty International.
 Most recently, the band has declared solidarity with the global Occupy Together movement.
Justin Cathal Geever, known professionally as Justin Sane, is the lead guitarist and singer/songwriter of the United States-based musical group Anti-Flag, a punk rock band formed in 1988 in Pittsburgh, Pennsylvania known for its outspoken left-wing views.
 He holds dual US and Irish citizenship and lives in Pittsburgh.
 His stage name was bestowed upon him by friends in Pittsburgh's punk scene.
1987 is the full-length debut of Doha/Dubai based hard rock singer-songwriter Naser Mestarihi.
 The album was released on June 17, 2013.
Naser Mestarihi EP is the eponymous debut EP of Doha based hard rock guitarist Naser Mestarihi.
 The release of the album marked the first official release of a rock album out of Qatar.
 All the lyrics and music on the album were written by Mestarihi, who also plays all the instruments with the exception of the drums.
A New Kind of Army is a punk rock album originally released by Anti-Flag on May 25, 1999.
 It was reissued by A-F Records on October 19, 2004 and is also the only album to feature only Justin Sane as lead vocalist.
 All other albums featured at least one song sung by either Andy Flag or Chris #2.
Life, Love, and the Pursuit of Justice is the first solo album by Justin Sane, lead singer of the punk rock band Anti-Flag.
 The album is entirely his own work, featuring his vocal and guitar work and demonstrating obvious influence from Billy Bragg's earlier recordings.
 The album is about, exactly as the title simply states, life, love, and justice.
Avenged Sevenfold is an American heavy metal band from Huntington Beach, California.
 Formed in 1999, the group originally featured vocalist M. Shadows (Matthew Sanders), guitarist Zacky Vengeance (Zachary Baker), bassist Matt Wendt and drummer The Rev (James Sullivan).
 Wendt was replaced early by Justin Sane (Justin Meacham), who performed on the group's debut album "Sounding the Seventh Trumpet" before leaving the band the following year after attempting to commit suicide.
 Dameon Ash (Frank Melcom) replaced Meacham for the album's promotional touring cycle, while lead guitarist Synyster Gates (Brian Haner, Jr.) joined the band after the album's initial release.
 Johnny Christ (Jonathan Seward) became Avenged Sevenfold's fourth bassist in time for the recording of the 2003 album "Waking the Fallen".
Naser Mestarihi (Arabic: ناصر شاهر صالح المستريحي; born 14 October 1987) is a Qatari born Jordanian-Pakistani singer-songwriter and multi-instrumentalist (guitars, bass & vocals) who is based out of Doha, Qatar and Dubai, United Arab Emirates.
 Naser is the first rock musician to ever officially release a rock album out of Qatar, the "Naser Mestarihi EP".
 He released his second album "1987" on 17 June 2013.
The Warped Tour 2005 Tour Compilation is the tenth installment in the annual compilation series accompanying the Warped Tour.
 The compilation's cover is a photograph of Anti-Flag guitarist and singer Justin Sane playing on the 2004 Warped Tour.